Jeff, They are not stupid questions.
1. Depends on the casino and state regulations. Ac chips can still be cashed in even if obsolete. However, most are probably worth more as a collectible.
2. Depends on your area of interest. Ac chips get Archie Black's catalog. Nevada chips get The Chip Rack. There are other good guide for other areas.
3. Click on the link to go to the CC>CC web page on cleaning chips