Probably the best advice you'll get.
But to answer a couple of your questions:
1. If you park directly in front of Smile, you may have a hard time backing out if more cars show up. I usually park way over on the right, past Elegant, and against the fence. More visible area.
2. I think Smile closes around 4am. Don't go really late. Best bet is early in the week and early evening. But everyone has their preference.
3. Depends on the girl, or if you go for 30 mins or the hour. If you pop very early and you're there for an hour you may get lucky. A lot depends on the girl and her comfort level with you, here's where YMMV. Some girls will do it just to see if they can get you off twice; whereas some girls will try to get you off quickly so they can finish the session. I don't think you'll have a problem at Smile if you stick with the well reviewed girls.
Good luck and review back.
K.