Thanks a lot Hubird,Wayne and Kensuguru for your replies!
Yes, 7/8 is a my conscious choice. I think it give a lot of surprise and can cause the spectators to lose one's bearings. (i don't know if my English is here intellegible...)
On the subject of the bass drum, i've already tryed to pump up his volume, but I've a throuble: in my mix i pass the whole drums to a single compressor, so if I raise the BD, globally the change is minimal. If I mix separately the bd and the other pieces I loose a lot of "power" (it seems a lot flat). I must admit that I'm not very expert in mixing, because I've mixed only few and easy works, so have you any suggestion about how to give more BD's presence?
I read about the compressor's side chain, but I never use it. Could be useful in this situation?