For some reason we have had a lot of trouble with getting the yorp to push correctly, how can we fix this?

Also, when I play the original Commander Keen, the yorp always comes towards me if I am standing near it, but our almost seems to randomly pick directions all the time.

Look for the variable "playpushed". Or look at the function push which is member of the class Player.

The yorp moves randomsly, but the values and seeds may be wrong. I noticed the same on vorticon.

You can change the probability if you want. That might help

NOTE: I think you will find the answer looking into /src/vorticon/ai/yorp.cpp. The file has mainly C-Code and is not hard to understand