As for the point of no return, well I arrived in Hinterland last evening, so I guess this is the best moment to change the build with one of the Tactician Renewal amulets in Haven. And thank you for the info on party builds Papacharlie9. I guess then that the banter between Dorian and Iron Bull are some where along the line of Alistair and Morrigan in DAO. 
No, you haven't reached Skyhold yet, so you don't have to respec. Unless you like some of the ideas I suggest below.
And no, it's not like Alistair and Morrigan at all -- Dorian/Vivienne is a bit closer to that. I'm at a loss to find a comparable banter to Dorian/Iron Bull. It just something you'll have to experience first hand.

When you see the name "Adoribull" in the forum, that's what people are talking about, Dorian and Iron Bull.
So, pre-Skyhold, this is my standard 2H build (absent Trespasser, see final note below).
1. War Cry
2. Mighty Blow
3. Block & Slash
4. Flow of Battle
5. Pommel Strike
6. Lightning Jab (upgrade to Pommel Strike)
7. Grappling Chain
8. Give Them The Boot (upgrade to Grappling Chain)
9. Easy Target (upgrade to Mighty Blow)
10. Charging Bull
11. Gore and Trample (upgrade to Charging Bull)
Those are the core skills of any 2H build. Some people prefer to go deeper in Vanguard, towards getting Livid (do you even have Livid without Trespasser? I'm not sure), some people prefer to go deeper in Battlemaster, to get Combat Roll or one of the Horns, but I like the above for a nice balance between the two.
Flow of Battle is a key passive. You will want to start increasing your Critical Chance with crafting or accessories once you have that ability. Cooldown reduction means higher ability DPS across the board.
In the very earliest levels, like where you are now, you can spend all day just using Pommel Strike to Stun and then Mighty Blow for combo damage. Or, you can grapple and boot and then Mighty Blow for bonus damage. Or, you can charge with Charging Bull and get a free ability at the end of the charge, like Mighty Blow or War Cry.
Post-Skyhold
Once you've completed the specialization quest for Templar, you can respec with an Amulet and go for something like the following. The goal of most Templar builds is what's called Wrath/Purge. Wrath of Heaven followed by Spell Purge does massive damage to stunnable enemies, which is most mobs.
1. Mighty Blow
2. Block & Slash
3. Flow of Battle
4. Pommel Strike
5. Lightning Jab (upgrade to Pommel Strike)
6. Spell Purge
7. Spell Shatter (upgrade to Spell Purge)
8. Champions of the Just
9. The Last Sacrifice (totally worthless, but needed to get to ...)
10. Wrath of Heaven
11. Embrace The Light (upgrade to Wrath)
That's the core Templar 2H build. That allows you to Wrath/Purge and do massive damage. The higher the base damage of your 2H weapon, the better. And if you critical hit, you'll be able to do another Wrath/Purge sooner.
Where you go from there is up to you. You can restore some of the abilities from the pre-Skyhold build:
12. Easy Target (upgrade to Mighty Blow)
13. War Cry
14. Grappling Chain
15. Give Them The Boot (upgrade to Grappling Chain)
16. Charging Bull
17. Gore and Trample (upgrade to Charging Bull)
Or you can go deep in Vanguard to get Livid. Or you can go down the right side of the Templar skill tree. Personally, I'd restore the pre-skyhold abilities, and go further to Whirlwind and Earthshattering Strike (the upgrade animation is very cool), but there is something to be said for getting Livid as well. The right side of the Templar tree is lower priority. Blessed Blades isn't worth an active slot (unless you have them to spare). There Is No Darkness looks good on paper, but by the time you have enough skill points to get it, 10% damage reduction is peanuts. It would have been great as the very first passive in the tree, but it's not.
Of course, all of the above is my humble opinion and your mileage may vary.
FWIW, once you have Trespasser, the above build plan completely changes. The priority for a warrior for me is Horn of Valor/Fortifying Blast. The first 5 skill points should go into that pre-Skyhold. Spamming that ability coats all party members with layers of Guard. Pretty near mandatory for Nightmare + Trials.