No Probs. hey I had a word with Steve Stahlberg about 5's during deformation, and he showed me some samples in a face on the cheeks where his 5s were and they were fine, so I think its a case of distributing those very well, which he does so...
Also, Vlad, with regards to rigging have you got Maya Pose deformer plugin? Its a better way to correct shoulder joint deformations. It works per axis like a blendshape but without the interference of another incoming shape so the way it works is more realistic, its a little more tricky to set up but once its done...it looks very good.
go here for the plugin: http://www.comet-cartoons.com/melscript.php,
scroll to 'posedeformer' theres a help tute here at http://www.tokeru.com/twiki/bin/view...yaPoseDeformer
Hope it helps out, I'll be using this in the very near future too