Front tire diameter, is it better to have a larger size front tire or a smaller for drag racing? Now I am not saying larger than the rear. I am talking about a 28" compared to a say 24". Smaller would be lighter.

the bigger the tire the more roll out you will have.

Smaller tires let the car break the beam sooner, taller ones later. A SuperGas car trying to get the car to break the beams as fast as possible would use a short tire to help. If you foot brake race, you can tune the cars reaction time by using different size front tires. The taller tires slow it down (reaction time), but the actual ET will be reduced by the amount the larger tires add to the reaction time. What you gain or lose from reaction time, shows up on the ET slip.

I personally like the tallest tire because I can leave the front suspension as is with alot of stored energy, and at the same time, it puts a little more weight bias on the rear tires.

It depends on the class your running the car in
I like to get my cars in as deep as I can so I have less distant to run to the finish line AKA., use what you like