There should definitely be some sort of indication when playing stealth so that you know if the enemy can see you or not. Our characters have a visual cone which in my opinion is pretty pointless, we know how far we can see just by looking with our eye's! What we need is for the enemy to have this cone so we can see how far they can see. Or some type of shadow thing like Splinter Cell had at one point to let you know when you're hidden
Being able to move quickly while in that play style is sort of dumb, it defeats the whole object of stealth if you can just move about at regular pace. When I play stealth of any type it's usually always better to move as slowly and as quietly as possible to avoid detection but if they can't see you anyway it sort of breaks the immersion made more frustrating when you've approached all quiet like and have to give a loud order over your comms, can't these guys whisper?