Emu XL-7 & MP-7 User's Group

Ive been learning more about my XL-7 for the past two weeks and Im 
coming to the conclusion that I love the sounds but the interface is 
confusing to me.Is there any particular setup for the XL to use it 
just as a sound source?I plan on using my yamaha RS7000 as my main 
sequencer.....Also (this is one of the things I didnt get about XL7) 
can you have differnt length patterns play together?ex A 4 bar drum 
loop play twice with a 8 bar synth loop..I tried it and got silence 
for the second 4bars of the drum loop in this example.

PS. I got the peter siedlaczk rom, great drum and string sounds but 
corny horns, just if anyonewanted to know.

Thanks!!