Less connections are better, especially if your going to have to use the lesser quality cable anyway. Plus if you have to use RCA jumpers you get another connection and more degrading of sound quality.
Interconnect length
I have a new Rega P1 coming in the mail. To hook it up to my system, I will probably need more interconnect length, so I will use an additional 3m interconnect (a decent one) to connect the P1 to my Rega Fono pre. So my question is: is this total length (3m plus the length of the interconnect that is part of the P1) too long, and will it significantly and negatively impact the sound?