#1 : what is an rv-8
#2 : what is a good dive bomber and how do i dive bomb
#3 : which fighter (not 110 or n1k) has the best firepower and good turning.
rv-8 is a plane hitech owns.
If i had to pick a dedicated dive bomber, it would be the SBD. This plane is tough and maneuverable. I would suggest, however, that you try a fighter attack plane to dive bomb in, maybe a p47, of f4u. Both of these planes hold tons of ordinance and dive well.
Dive bombing becomes easier with practice. To get you started, dive down at a 45-60 degree angle. Be sure to chop throttle to zero to prevent compression. Use the very bottom of your site, and aim just above your target. At about 1000 - 2000 feet drop your bombs. Obviously the lower you drop, the more accurate you are, but you are also more vulnerable to ack and GV fire.
Fighter are not about pure turn or pure firepower, in fact you rarely get both. IMO a good sturdy fighter to start with would be the spit IX. It is a relatively balanced package and has forgiving stall characteristics.
A good next step would be the 109-f4. This is a great plane, but is slightly more difficult to fly. With this plane you will need to battle torque issues, but it has better firepower (IIRC) and excellent turn rate.
To answer the best firepower in a fighter:
-190a8--This this has tons of heavy ammunition and shreds bombers like paper.
To answer the best turning fighter:
-a6m2 IIRC--Turns like crazy, not the best gun package (but still lethal). Its a fragile plane, and burst into flames if someone whispers the word first around it.