its a known issue, i am about to solve my problem by switching to a combo of Latest news modules, a frontpage slideshow and the old core frontpage component.

But you can expect some kind of answer like "Please send a support ticket."

anyhow, try to fine tune the most you can via cache (modules/content/components), gzip, optimaze and avoid images, be careful with the template you choose, and the components you buy 
Regarding NP you can "clean" the huge css file by removing the garbage you dont use (especialy comments) but i recomend you do that only wen you have the NP layout set the way you want.