PMC should spawn by default, in 3.5.0 there is even a dedicated addition in that regard, but usually they are being converted from other type of AI, you can alter that value in svm indeed.
If your sound issue affecting only you - if you hear other ai footsteps but not yours - I may assume you have enabled a hidden skill called - botSound, via SVM or Profile Editor, it can be seen in your skills if you did, you might need to edit your profile to remove it, or via profile editor if it actually has that value.
botsound worked, i didnt even know that was a thing. thanks!