I am interested to know if the mechanic of being rooted to the spot while firing is deliberate, or a limitation of the engine? If it is a deliberate design choice, then what is the reason? Would it not be better if we could fire and move simultaneously? Do other people agree or disagree or don't care? 

There are some weapons that allow almost full mobility, luckily, so it's a problem with a workaround, but it also limits what weapons I will ever want to use. Single shot skills allow the most mobility, and there are 3 weapons I can think of with effective single shot skills - effective as in they can hit multiple enemies with one shot - which are the lasgun, the shotgun and the grenade launcher. Using these single shot skills you can move almost normally, and be able to take out groups rather than having to kill every enemy individually.

I don't really like using anything that relies on full auto / salvo / channeled skills which make you immoblile. Maybe an option to allow free movement while firing, if it is possible?