it's in the options menu under radar beeps and radar name announce. use far render distance on big open maps and normal render distance on all others, no real need to mess with render speed unless you wish to experiment I've found.
Using a mouse makes aiming allot easier, but since their is a recoil system, some weapons are more shaky side to side than others. Eventually you learn how to correct your aim by using shorter bursts or groups of shots depending on if the weapon is semi or fully automatic, and then lining up again quickly.
At first it's hard though, it seems almost like the beeps are slightly off center, but maybe it's just unforgiving. Avoid corners when possible unless your hiding. Slow down, (avoid panic) and pay close attention to your aim, your going to die allot at first anyway right? may as well get a few proper shots in for practice first while your at it.
As you get more skilled you'll be able to use longer bursts and make slight left and right adjustments while firing even with all the noise.