Alright. Lately, there has been problems with ending events on RPG02 and RPG03. Does anyone know if there's an easy way of ending event's without those upsetting one time usable switches? I mean, on RPGXP, that has the local switch. Does RPG02 and RPG03 have those also? Or is there another way? Because this is really confusing me...

There really is no easier way to end events there.
If you start running out of switches, though, you can do other things:

If there's a switch in a place you'll never get to again for example, you can reuse that switch...

Also, variables can be used as switches, so basically you got 10000 switches.

Could variables be used over and over again? And I mean, like your using one variable to get an item threw a chest or somthing, throughout the whole game without making a new one.

And the switches...they could be turned off. But the thing is, they would activate the chest again for you to get the item all over or somthing...

Essentially there is no real "easy" way to go about doing this, although it isn't hard to begin with. It's just tedious. You are required to use a new switch for every treasure, etc that you make. Mainly because later in the game, if you turn that switch again you will have access to treasures that you got earlier in the game. I wouldn't suggest ever reusing the same switch or variable. The only way I would do this is if the treasure from earlier can no longer be accessed via teleport. Even if you do end up reusing it it still defys naming conventions... so its poor organization skills as well.

Also, as for RMXP's global switchs. They are essentially useless due to the same problems of reoccuring events. The only reason I use them is to test a feature in events before I tweak it. I then replace the use of the global switch with a uniquely defined one once the tweaking is done.