There is currently a script limit of approaching 200 AI scripts total allowed which may reside in the FPSC folders. The exact number is probaly a little erratic in each case but FPSC wont allow more than 200 currently.
I have 198 and thats my lot.
Dont try and hold anyone to this but this is to be possibly extended to 2000 and additionally upwards expanding thereafter without limit. I cannot say when this may become a reality but in an update - which one I cant say as I dont know and would not say even if I did. Its not my place to do so.
There is in my opinion which is currently unconfirmed still a map object limit - as I get one. It was supposed to have been removed in V1 development when I reported it and at one time I believed it to be so - though since I have had it return. - I have no idea exactly how this is determined by the engine - but you will know when you reach it. As it appears it relates to segments or possibly the enities (.x files) from which they are composed then when you exceed the limit your map will refuse to run if you load any further segments. I have asked for the map object to be looked at again and if possible removed comletely - though I have no confirmation that this will be so - as I did not seek it.
Both these limits will one way or another stop a game from being developed - the solution is to reduce the number of offending media quanities associated in each case which will allow the games or levels to run either in editor or at compiled game run time in cases where each is applicable. So dont panic and dump your levels if you reach a limit thinking you cant repair them - just recongnise it and fix it and they will run again.
As to poly limits - theorectically as far as I know there is no imposed engine limit in source - but there always is in practice I guess.
"I am and forever will be your friend"