I am not an expert but....
1. This depends on a lot of factors like your goals, pond fertility, predator density, etc. If you provide more info, one of the experts may chime in with their recommendation.
2. This is variable. Under normal conditions they should be about 2" inches after the first year. After the second year, they should be 4-5". You can expect another 1-2" of growth in the third year. With some management (feeding, etc) you can greatly increase these numbers. Consequently, if the population is overcrowded, you will have less growth. Do a search on this site for BG growth. It is way more complex than I ever imagined.
3. Avg lifespan of a bluegill in an aquarium is around 7 yrs. 13 year olds have been documented. Of course, in a pond, the vast majority are eaten in their first year.
I hope this helps.
