also, is it a big deal to have an extra 100g in each wheel rim for accelerations? I'm considering selling my tubulars to race on clinchers. I never train with tubulars, and it makes no sense to me to have my best wheels sitting around waiting for big race days, which only comes around like once every 2 months. I don't even use them for the training series.

100g is my approximation on the weight difference of the rim, tires (and tubes)