Critique sought

I've put up some notes towards a conlang at
http://www.people.cornell.edu/pages/bjm10/Gloling/praxname.html

I confess that it's not 100% original--it's based on the Glorantha
setting.  Thus, I am somewhat constrained.  If I want to remain "true" to
the "source" material, there is very little I can subtract.  A few things
in particular bother me:

The vowel structure seems lopsided.  Any suggestions on how to fix it?
I think that I've made a goof in adding a labiodental nasal--the "source
material", since it was written by a Californian game designer with zero
linguistic background, uses a vary English implicit phonology (from what
I've been able to gather).  Would a language be likely to differentiate
between a bilabial and a labiodental nasal?
The "terminal glottal stop goes away sometimes" rule doesn't quite work
for me--is it nonsensical?  (All the "combinatorial" rules are my own
design).

Anyway, I'd welcome the critique.  I've got more material, but this is
all I have on the Web.

Thanks.