Since I had my toasters installed on my 360 I noticed a bit of buzz on the B and high E. I can't really tell where it's coming from. It's not audible through amplification but I can hear it when I play unplugged. Is it because of the floating bridge, saddles, etc?

I've noticed a few folks talking about buzz on bridge/saddle or tailpiece. I made sure all of the nuts on the strings were firmly in the tailpiece.

Are the bridge height screws adjusted correctly? If one of the treble side screws is minutely too high or low it could create some buzz you describe.

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As I get older, my music gets softer and my shirts get louder....

When this happens I test it by making the instrument buzz, unplugged, and press my finger to try to silence the noise. This way you can figure out which saddle/screw/etc. is making the noise. Usually something needs to be tightened a little. Happens on my bike all the time too.

I think I am getting the buzz from the bottom spring of the bridge piece. It seems more stretch out and it's rattling.

Try the truss rod cover. That was the culprit on my 360/12.

If you had no buzz prior to installing the toaster pups, then in the process of putting things back together the bridge and screws have moved slightly in position.
Maybe having no strings on it for a short while and working on the pickups you have unintentionally altered the bridge position ever so slightly.

It should be relatively easy to fix but it can require a bit of patients.
First get the bridge to to height you want, try to at first get the bridge level with all screws at the same height. However after this if you have a buzz and it is still seems to be coming from the bridge on the treble side. it is then a matter of ''tweaking the screws until the buzz goes.

In the end it may appear the the screws are at slightly different heights, don't let this concern you, do try to keep the whole bridge fairly level, but don't rely totally up the screws to calibrate it's position as you attempt to remedy the buzz problem.