To many products and plugins?
 

Does having to many products or plugins effect performance of your forum site much ?

Yes, it effects performace. Turn it off and on to determine how much. :D

Every Plugin adds Code and thus has an impact on performance.
However, if the Code is optimzed and you don't put too much into Plugins (=> include files), you shouldn't notice much difference.

A lot of them use queries, some even use 3 at a time per page....so watch it

Not really true. Some hacks dont even add queries. Others might add one query. Same as back in the vb3.0.x days. The bad hacks might have alot of useless queries but thats a bad hack for you eiither way.

I mean I along with others design code to be as optimized as possible. I have so much custom code running on my test board its not even funny. Yet the board still runs almost as fast as a stock vb. I mean my load times on any given page are about .01 second different at most on my server. I mean some of my code changes have even managed to make vbulletin even faster without even meaning to.