If a purchase is made and I download the App, and I delete it later on at some point, Do I have to buy it again or is my phone on file as having purchased app before?
From the Market App>>Menu Key>>Downloads
A gun in the hand is better than a cop on the phone.
Only the Skilled Survive
A computer lets you make more mistakes faster than any invention in human history - with the possible exceptions of handguns and tequila.
Drill Sergeant Frick's Rules For Un-armed Combat.
1. Never be unarmed.
2. See Rule #1
USMC rule # 23 of gunfighting: Be polite, be professional, but have a plan to kill everyone you meet.
your purchases are linked to your GMail account, they really have nothing to do with the phone. Once bought, they can be downloaded onto any android phone, any amount of times (with your account logged in)