sounds to me like you are selecting the vertices by hand instead of by vertex group. most source models should already have vertex groups, so I'll show you a convenient way to delete faces without anything touching what you want... usually.

• in edit mode, select all the faces of your model.
  
• go to the properties panel, and select object data.
  
• Look for the vertex groups tab.
  
• scroll through and look for the groups of geometry that you want to keep.
  
• select that vertex group and click on the deselect button.
  
• repeat for any other groups you want to keep.
  
• delete it.
  
  if the survivor model has multiple materials, you can use that section of material, to deselect vertices you want to keep for your survivor as well.
  
  a warning however! some vertex groups have stray vertices beyond the expected body point. using this method is not perfect, but it should get the job done, be patient and you'll get through it.
  
  Finally, if you have no need for the model's shape keys, you can always use tris to quads to make selecting edge loops easier.

it's mostly a naming convention, make everything the same, so It's easier to work with. flexes themselves are created in blender with shape keys.

well, my problem is solved!

despite these errors, all I wanted was to preserve the imported model's shape keys. it turns out, everything was fine, and "Always show the current shape for this object" was turned on during the import.

turning it off did what I wanted, and that was to make the shape keys workable.
it always ends up being stupid and simple for me, thanks for putting up with it!

Hello. I am trying to import a model so I can make animations in blender, I am having a strange problem with the shape keys/flexes of the character. upon choosing the shape keys in object mode, the shape key shows the flex at 1.00. the shape key value slider, however, shows it at 0.00 and is greyed out.

upon checking the console, it seems that none of the vertices in the .vta file were actually importing to the model. I do not understand why this is happening as I have little experience with the Source Tools. my decompiled files have an .smd, a .vta, and a .qc. I have tried importing with both multiple files and single files, nothing changes.

another thing I've found strange about this model, is that there's a SNAFU with the naming conventions, the fingers of the left hand had them listed as "ValveBiped.Bip01_l_FingerX", instead of "ValveBiped.Bip01_L_FingerX" being lower case instead of upper. would this contribute to the problem I have? If these do contribute to the problem, would I need to fix them before I import?

thank you for your time.