it only takes 5 bullets. there’s most likely not enough locked doors for it to matter how much ammo you use to open them, as the default ammo count you start with is enough to last. not to mention you can just refill by finding another pistol.
time to aim at the lock is irrelevant, just get close to the lock and shoot.
if you are shooting the door open, most likely you’re not doing it in a place where you could be spotted or where somewhere could hear the shots/impact. same with the lockpick
however, the lockpick animation seems to be way faster now, and that might compensate for being able to shoot open doors. and you’re right, there is more risk in using the gun. but still, you’re always gonna have a pistol by default, unlike the lockpick, so it worries me a bit.