Yeah it's great that your backstory isn't too deep so that you fill in the details that the game leaves out.
Like I said it's all about your own role-playing preference. Some like to play a character that's more rigid and defined (like Hawke, Shepard, Geralt and even something like Revan from Kotor or the Vault Dweller from FO3) while others prefer the blank slate with minimal guidance approach (like DA:O and I or the protags from Vampire: The Masquerade-Bloodlines and the last two Persona games). Some don't even like their hands to be held at all (with things like MMOs and TES) though that tends to be way to wide open for my tastes. If we were talking about a character in a story driven action game that's entirely linear, then I'd agree entirely with your point. But for an RPG where we're "creating" (at least somewhat) our own character, I find it perfectly acceptable for it to include minimal backstory.
You're really limited in what the inquisitor can be in my opinion. If you're satisfied with the very neutral personality the inquisitor is stuck within then it's fine but if you want to play a variety of characters...well good luck. None of the options are passionate or extreme even when the situation warrants it (why can't my Dalish elf comment along the lines of "this place was built on the bones of my people" while at Halamshiral, etc...). I have to ask though, how do you see the inquisitor as NOT being pigeonholed? You can't be evil, you can't be racist, there is only one ending, none of the side quests have any character building/role playing options which leaves you with only the short main story and companion quests to do that.
I did think the DA2 personalities were TOO extreme most of the time and switching between tones made you sound like a lunatic. I just wish they had found a balance between extreme manic mood swings at all times and a neutral glass of room temperature lowfat milk.
I'm not saying the Inquisitor isn't entirely pigeon-holed, it's just less so than Hawke imo. I understand the limitations in video game plots are a lot stricter than any other fictional medium, it's essentially impossible to not get locked down a certain path. In all honesty, all the DA games take you down a straight line (just like ME and most games that offer the illusion of "choice"), I just think DA:O and I mask it a lot better than 2. As for the Inquisitor's neutral personality, I'm not sure I entirely agree with you. My first two characters that I've put the most time into (finished the game with one, almost done with the other) are plenty passionate and with my current character, completely unwavering with her somewhat radical ideals. And my view of evil could be entirely different than yours, but I think Inquisition can let you become pretty scummy (or at least cold in a morally grey sense, which I appreciate a lot more than plain old "evil"). I think a lot of what determines your character's personality comes down to the VA's performances as well (just like maleHawke is more believable than femHawke as a stern, brooding type while femShep is much easier to play as a BAMF than maleShep). I personally enjoy 3 out of the 4 VAs (the only one that doesn't do it for me is the American female, which as you wonderfully articulated, does have the tendency to sound like "room temperature lowfat milk" lol). I actually enjoy Alix Wilton Regan's (British fem, also Samantha Traynor's VA) performance quite a bit (not as much as Jennifer Hale, but definitely more than femHawke). I wholeheartedly agree with you on the lack of race specific dialogue though. I haven't put much time into the non-human races, but the little I did it didn't seem like there was enough of a reaction in certain areas (and out of the three, it seemed like dwarfs got the most, which is the least interesting of the lot to me).
While I'm writing this book (yes blah blah tldr) I thought I might as well address this whole side quest flaw that everyone seems interested to blow out of proportion (and by side quests I specifically mean the story driven ones, not the fetch quest time wasters).
Are the side quests in Inquisition disappointing? Yes
Are they the worst in the series? Yes
Should Bioware implement better side quests in future DA installments? Yes
Should these quests discredit all of what Inquisition does right? HELL NO!!!
Honestly I don't see why everyone is so stuck on these side quests (or lack there of). I know side quests are great and all when they're executed properly, but it's not like they should be the one thing everyone goes on about with their dislike of Inquisition. There's even some good ones in Inquisition. Specifically I enjoyed The Fallow Mire, The time frozen temple in the Approach, closing the rift in the lake in Crestwood, the haunted mansion, capturing the three keeps, the dragon hunt (though it does take the fun out of it if you prepare too much for them), I even enjoyed the shard collecting somewhat (and I know some will say that's still a fetch quest, but it does have some traces of story. You go to a place called the temple of SOLASan for Pete's sake). There's really one to two good (not great, but not bad either) side quests in each area that are entirely interesting. I think a lot people are turned off by the free-turning camera and think if anything in game lacks a static cutscene, then it must be unimportant and skippable. It seems like there's a lot of people blinded by hate when they should be focusing on how good this game's cast is (probably the best in any Bioware game imo and at least the most consistent quality wise) and how damn near perfect 7 out of the 8 main quests are. The only one I was disappointed in was the last, and that's mainly due to the high I was experiencing from how good Mythal was. But honestly, the post-credit scene kind of made up for it.