I think they are very cool and I would enjoy it even with classic HL enemies and weapons (and I think exactly the opposite - that they do fit surprisingly well in KFmod environment), though the idea of this mod/game is to make it a KFMod prequel, not a HL1 mod, so yes, enemies and weapons will be replaced with those from KFmod (or maybe some elements from KF1 too).
Zombies have to be reskinned too, probably, their look doesn't fit good for environment.
Yes, I will replace it with old KFMod zombie model. Or maybe create new one
I think they are very cool and I would enjoy it even with classic HL enemies and weapons (and I think exactly the opposite - that they do fit surprisingly well in KFmod environment), though the idea of this mod/game is to make it a KFMod prequel, not a HL1 mod, so yes, enemies and weapons will be replaced with those from KFmod (or maybe some elements from KF1 too).