Quote: "i know its not a pc problem so i am wondering if its the mobs being on the map from the start or something i placed that is causing the lag"
Yeah trigger spawn them dude.
Never have more than 6 or so at any one time and you shouldn't experience much lagg.
Just add more until the lagg sets in, then you know your limit.
Even as little as 4 enemies at a time can be hazardous to the player depending on how you set them up. (high health etc)
Quote: "also would it be better to create a trigger zone to spawn my enemy's and other objects thanks in advance."
Only the dynamic ones. (mainly characters)
The static ones shouldn't make much difference.