The answer really depends on your driving experience and your goals. If you are at the top of your game in Fla and going for a big TT win I would suggest looking hard at your rulebook first and choose tires and alignment very carefully. If you are going out for a DE with the club, don't overthink your setup. Get a good neutral camber setting close to what I listed earlier and go out and have some fun. A car with understeer can still be driven quite fast, you just drive it a little differently. Too much tinkering with the car and you will miss the joy of driving flat out
As to zero rear camber... I wouldn't do it. You may get a bit less understeer but the tradeoff will be tragic outer edge wear on your rear tires. Not the best plan.