actually usualy it's -3 to hit..,-2 on the first shot....long range, move, and then multiple shot.. (usualy you end up moving as that's the str. of the x-bow w/ the high speed of the elves.
You've got my opinions already on them. *Shrugs* the only effective use of x-bows i've EVER seen is running them forward, firing, then moving back and keeping up the firing with MASSIVE number's of shots (the guy had over 50x-bows) + the 4 reapers...
DE shooting requires a VERY commited effort. Your better to go for Shadow Warriors, pull the x-bows and the reaper and the harpies, and get a block of black gaurd or something.
or just pull the x-bows and put in a second reaper.
like i said tho, you know my opinion already. I like the list a lot better than the other ones, i feel it's very well rounded, and if a lack of flexability in models is a problem i think it's a solid list, and you should play test it as is. I think you'll find the shooting isnt' doing what you expect it to do though (unless it's to take out scouts/light calvery, thin down heavy calvery VERY Slightly) it wont' be touching blocks of infantry and most heavy calvery will waltz past it due to LOS restrictions. (your killing field will be VERY small) however, to hold a flank, the x-bows and the reaper are probably sufficient! =)
Nice list overall, very balanced, good comp.