Like cracking it open instead of opening it all the way? I don't see the issue. If you open it when the guard isn't looking, they don't see it and don't react. Open it while they are looking, they get curious. I crouch when I open them in a hostile area.
While I agree the AI is sometimes sporadic, they do react to noise and and changes in the situation. Leave a body behind, they get alarmed. Get to close and noisy, they see what's going on. Hell, I use distractions all the time. Throw a box to make noise or even set off and explosion. I used a vending machine to block a doorway so the could not get to me. That was funny.
One the controls, I totally disagree with you here. They are slick and have had zero issues. I find movement in stealth easy