Pseudopsycho If you got the dlc armour packs (spoils of the avaar and spoils of the qunari) then you will have a bunch of light/medium/heavy armours dumped in your inventory as soon as you reach haven proper. You can equip any of those, but otherwise apart from that armours are class restricted unless you download a mod that unrestricts them. There are some armours that are also race restricted. Humans have more unique armours than others, qunari have the least (something that the spoils dlcs sought to make up for).
You can use a gamepad if you'd prefer. Menus and general running around are a lot, lot better with a gamepad, but I pause a heck of a lot to assign commands and gamepad is abysmal for that, so I stick with kb&m. Anecdotal evidence suggests the majority of people who tried switching to a gamepad never looked back (I'm the minority).
Quality settings: absolutely keep meshes and textures and shaders at ultra. Everything else is up to you. I recommend dropping the one that controls cut-scene blur (one of the places it can crash if your system is overtaxed is during some cutscenes). You can lower water without much difference, drop spell effects by one (any more you might start seeing a problem). Tessellation need be on no more than high unless you really care about your rocks being as round as possible, it's resource intensive. Vegetation reduces the density and I think the draw distance and can give you back quite a few frames, particularly when you go to the area you're going to next and others like it. Can't remember what it's called, but there's one that controls the level of terrain detail, mostly in terms of draw distance but also in terms of how many extra little bits of detail will be lying around I think. You can drop that one a bit.
SSAO and Shadows are huge performance-sinks. Set it to SSAO, not HBAO or HBAO Full. With your card you should have no problem with SSAO. Shadows can go down to high instead of ultra - they're a bit softer but I think that's more realistic anyway, and draw distance isn't quite as far but I doubt you'll notice.
Use post-process AA instead of MSAA. Image quality won't be as good but you'll gain frames. Best option is using ReShade or SweetFX so you can add SMAA, which is pp AA (and therefore very lightweight) but one of the best you can get. If you're happy with the in-game version though don't worry about it.
Cutscenes are locked to 30 fps and have been notoriously choppy and shit since release. Don't be alarmed if you get lags and stutters during them. It's quite normal, unfortunately. Optimisation is utter shit, loading and menu screens can take up to 100% of your CPU (rumoured to be because of Denuvo drm, which makes multiple calls for verification per second or something, idk).
I crash occasionally in some menus (potion equip being the main culprit), but only when using kb&m (the menu design is different for gamepad) - save a lot. You can only have 250 saves, so delete what you don't want once you're sure you don't need it (or be sensible like me and back them up). Try to do a fresh save each time rather than relying on quicksaves or saving over old ones.
Ask away with anything else, and enjoy - you're in for quite the ride (definitely get the DLC - in particular Trespasser is mandatory, and I'd never usually say that about any DLC but in this case it just is. And watch the credits.).