The arms and legs for Marina and Pearl aren't properly set up for IK rigging. https://imgur.com/a/z3DP2SS

The bip_hand bones need to be attached directly to bip_arm2, and bip_arm2 needs to be directly attached to bip_arm1
bip_foot bones > bip_leg2 bones and bip_leg2 bones > bip_thigh bones in order for the IK rigging to work. Otherwise the legs would need to be manually posed and would be too bendy like the image.

Also, there are redundant bones that do not affect the model when manipulated, bip01_r/l_hand, leg_2, leg_2sub, and foot_r/l bones

The models look good so far otherwise and I can't wait to see where they go!

Making a IK version for Marina and Pearl ask some effort to do that, I currently try to create a IK version and make attempts in SFM.

Not sure how much this belongs here, but the stitched mouth is the result of the importer merging nearby verts together.
What Blender importer are you using?

Blender Source Tools latest version.

Originally posted by OctopusHorizon:

Blender Source Tools latest version.

I think that's the issue, since Source Tools exactly isn't friendly to face rigs.
SourceIO is another (imo better) Source import addon that doesn't have this issue

Just find the SourceIO download link and i try if it's work or not.

Okay, The Module is working on Blender and the mouth is not welded anymore BUT... when i assigned the mouth on Blender then i compile on GMOD, It's welded again in-game...

Image:
https://steamuserimages-a.akamaihd.net/ugc/1880829818136648907/7A095A5964F3449E81E098DD6641F5914A6F3429/?imw=1024&imh=639&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=true