Q&A

For a low idle speed, I would start by making sure there are no vacuum leaks, then clean the throttle body.
Riding the brakes will only wear them out sooner, you shouldn't see any other issues.

a. your throttle position sensor is prolly bad.
b. you need to have someone replace it for you. dont take it in, cuz the shop will rip you off on the labor& its so ez i can do it & im a dumb girl. however, an adjustment may need to be made to the air idle sensor at that time, which is also simple enough to do at home for free, or the "service engine soon" light will keep coming on, even though there's nothing wrong with it.(I have been through this twice with my buicks!)
c. you arent going to ruin your brake system, but may cause slightly excessive wear on your brake pads. which is only a problem if your brakes are already in bad condition.