Words for "smile", "frown" etc. in a (more or less) minimalist language

I was thinking today about whether and how to lexicalize facial expressions
in {gjax-zym-byn}, my personal language.  gzb is lexically minimalist
in most respects, and I was fairly sure I could derive words for such expressions
with existing wordstock.  I had already derived words for "thank", "praise",
etc. from a root meaning "say" plus a mindstate morpheme (i.e., derive various
words meaing "express one's mindstate being such-and-such"), so I figured
I would try the same for these concepts.

At first I tried on an unwieldy compound:

taxlm-vim-pxax-pym-zox
head-[front of, part]-form-amusement-[active verb]

("v-i-m" is a three-morpheme postposition meaning
"part of, situated in front"; e.g. "taxlm vim riqm-nxiqw",
head in-front-of(part) eye(s) - the eyes in my head - as opposed to
"taxlm vin riqm-cxa", head in-front-of(touching) glasses - the glasses
on my face)

Then decided to try out a new root word "wyr" meaning
something like "facial expression":

wyr-pym-zox, smile (action)
wyr-pym-van,  smiling (state)
wyr-hqum-van,  wearing an expression of terror
wyr-wlax-van,  looking utterly bewildered

etc.  But then I thought that maybe I could just stretch
the meaning of "pxax" (figure, form, shape...)
to cover "facial expression" or more generally "mien",
"comportment".... and use it just as with the "wym"
experiments:

pxax-pym-zox, to smile with amusement  (e.g. at a joke)
pxax-pwiq-zox, to smile in delight (e.g. at a baby being silly)
pxax-beq'laxm-van, to blush with embarrassment
pxax-geq'gxu-zox,  to frown with disapproval

I'm not sure which of these I'll go with. It depends on whether
I (or any of y'all) think of situations where the further
stretching of the meaning of {pxax} would lead to
undesirable ambiguity.


- Jim Henry
http://www.mindspring.com/~jimhenry/conlang.htm