For me the player walking "physics" has always felt really weird, like he's moving in molasses. It makes me sick. Is there any way to make his movement more like modern FPS games?

If i remember right , there was a number of mods to make the game more smooth like activate mouslook with E, soofter movment, etc.but i don't know if they're still out.

Esp. if you take into mind, that a EE is out allready and a modern re-release is coming.

no, there is no way of getting rid of PPP (player potato physics) at the moment. it has been suggested to the devs as an enhancement, and they are not opposed to the idea, but this is not a trivial change, so don't expect it anytime soon.

Ok, I got the source port version, and the E key for freelook is definitely a plus.

Now I'll just patiently wait until I'm not a potato. I mean, it's been 25 years, so what's waiting a few more?