These patch notes made me give my thoughts too.
I've read this forum intensely for 2 months now, and when i bought GTX 970 game became playable. Just in time for this:
http://blog.bioware....black-emporium/
and boy! was i excited!
"Patch 5 will be the biggest patch we’ve released to date, and it addresses a number of key concerns for our community."
Until.. now. None!! NONE of the key issues were addressed in any way. I'm forced to play with controller and like to play with nightmare + friendly fire, so it can be overwhelming at points..
But i love the lore and the setting, i just wish they would finally fix the damn "tactical" camera. To get stuck in objects with cursor.. really? Wow.
Played 70 hours so far.. gonna complete the game, just because before i started playing this, i took a trip to memorylane and played origins again (this time all the dlc's with ultimate edition), finally played Da2 through too, and even went and read Asunder for this game. So. I was set with my new graphics card!
Well... you all know what i mean.. it's been way too long. They can't fix any of these kb+m, taccam, inventory etc issues. Its the engine or something. Just need to accecpt it. 
Firstly, patch 5 has not yet been released.
I do share your frustrations and I assure you, it is NOT because of any imagined game engine limitations they can't fix the issues with the game.
The reason they can't fix these issues is because they are simply too incompetent.
They even make public excuses about the engine being so complex and it being so very difficult to do certain things.
But meantime back at the ranch, they managed to create physics and animations for 4-legged creatures - something they said could not be done, but they can't fix STANDARD things like proper KB&M controls, Tac Cam behaviour, UI, etc. etc.
Battlefield 4 uses the exact same game engine as DAI. That game has a ton of UI customization options, proper key mappings scheme and whatnot.
Bioware simply FAILED to deliver on their promise of a "PC" game.