You may want to try rearranging the cr2. I've found that sometimes Poser works better if you have tree sections in certain orders.   It reads things from the top down in the cr2, so a little judicious rearranging can do interesting things.  I recently had an issue with a conforming robe because I had the left arm section before the right arm, and it caused no end of weird little issues.

Looking at the hierarchy tree in PFE, I see that you have the hip section, then both leg sections, than the torso and arms.  Most poser figures have it the other way round, hip, torso, arm cascades and then the legs.  You may find it changes if you move those areas around. Remember also to sort the figure Weld and AddActor sections the same way or poser may barf. Avoid the poser figure setup room where you can, its a screwy module. I mean, more than usual even for poser lol

as for the head scaling .. yes thats easy enough to do via a propagating scale dial (as long as you havent done the weird thing daz did with the back of the neck cut on v4) or with a simple morph. I'm almost inclined towards using a morph, since that will be easier to add into clothing ... but thats 6 of one half a dozen of the other.

As for cascading scale changes via ERC statements .. I've figured out a relatively painless way to incorporate them in clothing items so that they more or less work in poser and definately work in DS.  Gareees Lycanthrope Plus set has some extreme and quirky scaling built in to some morphs and I managed to transfer that nicely.

On the arm thing... once you have lengthened the upper arm, the rest should mostly be adding x amount to the xtrans value of all the child bodyparts. Not fun by any means, but certainly feasible.

Oh and on the alternate uvs question someone raised a while back ... I figured out a one-click pz2 solution in poser to swap differently mapped identical geometry live in poser. But you do need both obj files around, so it doesnt obviate the need for rt encoding, alas. I can send you an example pz2 if you are interested. Its less than 10 lines long :)

Lyrra