Man, don't engage Asdrubael in conversation.
It's fine to point and laugh but if you try to talk with him, he'll start claiming that Tevinter is 95% elven.
Seriously.
I am sure that will be no proof for such bullsh*t what never happened, cos i am never said such things, nothing even close for what that you just made by yourself and claim that i was write something like this
so please atleast lie harder and smarter next time 
I was considering reacting to it myself, but there's so much bias, hysteria and incorrect info in that post that I felt exhausted just by reading it. So thanks for taking it upon yourself. You have my sympathy.
Ok lady please pick and reveal at least few or just one incorrect info what i was posted here if there is so much as you talk 
Not supposed to happen, but it happens. Probably more often in the more permissive Circles.
But yeah all that stuff you listed can happen. Most of the time it does not. Mages and Templars are Others to each other. DAI however changes all that, or at least changes it to a degree that we can expect more positive relationships between the two (or what remains of both factions/types of people). The kinds of changes beyond that, depends on our choices and how we interpret the ending.
Structurally, the Templars were absolutely not supposed to be anything but cordial to Mages and only helpful enough to have safe operations of the Circles.
Rape stuff and beating mages just for laught, yes that the only stuff what is not(as any relationship with mages what templars do too) supposed to happen
But nothing in Circle stop members of the Templar Order and protect mages by the law and Templars do not have any punishment for such as everyone close eyes for such things
...all other as hunting and draging in circles or killing, torture, executions, right of annulments. tranquil it is their job as following the orders without doubt exept if they are clearly violate orders of Chantry and Seekers, and actuallly orders of the Seekers are more valuable for Templar even then a Divine orders what was shown in Asunder, cos even with the high ranking enchanters from the elite Chantry Circle who lived near Divine herself and was working near Divine herself showed how it was bad and those are revolt too
Structurally Templars are the zealots army of Chantry-Seekers(who perfectly know that there is no need to Templars existence(cos Templars was must be created via Seekers way and Seekers does not want that) and lyrium drugs exept for Seekers need only what was revealed by lord Seeker), they follow the orders of them and kill mages, "heretics" and nobles who try to not obey Chantry as you see in Kirkwall and can learn from lore
Templars never help or teach mages in Circle only observe and punish/execute/tranquil them if they try to run from Circle or consider(and there is clearly no straight rules and restrictions about what Templar can consider as bad to kill mage exept only not obey orders of Templar and clear deamon turning and blood mage stuff) them dangerous, and thats all....and there is no limitation of Templars powers what they use for mages and nonmages(who is not a nobles what they try to secretly kill) too
In DAI ending we see the end of old Orlais Chantry as Seekers and Seekers Templars who can be banned of reformed to serve Cassandra or Mages and be more like in Tevinter and Nevarra, no matter what they will not have rights and powers as they have before, they are not the same Templar Order what South Thedas have for 900 years
Enchanter Ellandra, from the Hinterlands, when you recruit her says that Mattrin was her friend before they were lovers and that she had friends with both Mages and Templars that she lost thank to the war.
So I do think friendship were possible.
Look at Irving and Greagoir - they seemed hostile to each other at first (if you played Mage Origins) yet Greagoir says to the Warden that they would only accept Irving being alive as proof of the circle being safe and is kind to him when Irving is brought back - indicating that there is some friendship there.
Ser Thrask was a kind templar who tried his hardest to protect the mages, telling the group - if you convinced them to return to the circle - that he would protect them. He is even seen helping them in a later quest (although it was misguided) but it showed that there are elements.
I get the feeling that each circle is different on how firm it is regarding friendship. Kinloch Hold seemed quite...lax - if one could say that - regarding friendship between Templars and Mages whereas the Kirkwall Circle proves that any type/hint of friendly feelings (even between mages) were discouraged due to Samson being kicked out and turning Karl into a tranquil due to his letters to/from Anders.
(I have never read asunders so I have no idea if there are any friendships).
So I think, on one hand - templars and mages were encouraged to at least talk to each other, that way if one of them have fears, they would be able to try and assuage it but on the other hand, they would have been discouraged not to form too deep friendships in case Templars were unable to do their jobs.
first i said about this "Templars" who was become true friends-lovers(cos many just be like Saddat or rapists like ser Otto) with mages and protect mages from Templar Order as many have relatives who are mages what is forbitten if you are not a noble and those Templars hide that info
they are not a Templars and they are against Templar Order and Seekers, they are the worst Templars in the Order who are betrayals of Templar Order
Thrask, Carver(Friend of Malkolm Hawke), Evangeline, Reimas(The last flight book) all this "good Templars" are not a Templars and go against Templar Order
Enchanter Ellanna from Ferelden was a Aequtanian-mostly a Loyalist mage and her lover(what even said in his letter) go agains Templar Order, and they were in Ferelden what was have a bad Orlais Chantry controll and mages since war with Orlais and the old Gregoir poor command and Irving controll, bribe many templars(we clearly know it in DAO and have quest what was involve there) by lyrium what they have from Orzammar...and yeah there was almost no Chantry controll over Ferelden circles after Loghain involment and after 5 Blight what we know from DA2 and Alister/Anora protect mages from Chantry and Orlais Empire
Gregoir was "good one" when he was old addicted Templar and was bribed by mages(who with Irving even give many weak rogue ones to him to he was belief that they are loyal) with lyrium for his addiction and especially after they save him from assasin of apostage blood mage what was try to punish him for all bad stuff what he was do against mages, and younger Grefoir was a pure bastard and even beat pregnant mages like Veness who have a child from a templar Saddat
Templar Thrask have a mage daughter in Circle what he hide that she was his daughter to protect her from Templars, and she was become crazy of Templars care and run as died after begging and turning herself to deamon when she was hunted to a corner and was to be killed or raped
Thrask is died cos of plothole(as with Orsino who turn himself to deamon no matter what, by this at least can be understandable that everyone for who he was care was die and he have no reason to live so he is try to kill more templars before they kill him) that some mage and mages supporter ex-templars belief that Hawke was a Meredith agent even if he was kill all of Meredith Templars and help mages...and yeah Thrask with others try to peacefully go against Meredith and Cullen ruleship over Kirkwall but Cullen stop him as others to even do a reports to a new Divine about Meredith
As i said the only Chantry Cirlces where life of mages(mostly enchanters and high ranking, but not aprentices) was slightly better is the Chantry Circles who was in countries with smaller Orlais Chantry and Templars controll and where Templars was bribed with lyrium...and we know that Seekers with Templars after they was know about such do a right of annulment there as in Rivain and others and this is why mages revolt after Kirkwall and other stuff what Templars and Seekers do
Friendship as any relationship with mages is banned for Templars and Templars Order as Seekers(do not put Cassandra who was most of her life serve as Divine bodyguard and not know anything true about Seekers and Templars) is propoganded that Mages are worst living things who are sinners, many loyalist mages was so propoganded that they believe that they are wost thing ever and it would be better if they would be traquiled, and they are