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

Hello, I'm considering buying an XL-7.  I would like to use the built-
in sequencer to allow me to compose without having to boot my 
computer, which completely ruins my concentration.
On the Yamaha Motif and the RM1x, I am told that there is the 
possibility to loop individual tracks (called 'phrases') in a 
pattern; is this possible on the XL-7?

I am asking because the way I prefer working is by looping a bass 
drum & hi hat on something like 1 or 2 messure, and then add more 
tracks that loop on bigger intervals.  It's my understanding that the 
XL-7 has an 'extend-to' function, but that it essentially copies the 
data to the full length of the pattern.  That's not the same 
workflow, because it's a copy, so if you change that 1 messure, you 
need to copy it again.  You end up doing a lot of maintenance work.

So, what are the options on the XL-7 to do this? (You can't play more 
than one pattern at once in song mode, right?)

Is the sequencer on the Proteus 2500 the same, and is it possible 
for EMU to add features to the sequencer, or is only small tweaks 
possible?  Why is the pattern lenght limited to 32, is this a 
hardware limit?

Finally, if I put the Orchestral ROM cards in the XL-7, do I loose 
access to any feature compared to the virtuoso module?