Nganasan (I had to look it up)
The forbidden endings:
*ea, *er, *ia, *fy, *ic, *ky, *ly, *ll, *on, *ty, *um, *us, *xo
and all the other two consonant endings that don't start a word.
And I guess it won't be long until we add *ng.
About *gh I don't think it's that bad. It haven't been used often, so I see no reason to add that ending yet.