Thank you, I really appreciate your help. I did not think to check that one. I have found and disabled it.
I strongly agree that the behavior is wrong. I was also very distressed about the automatic updates with no indication they even existed (because there was no setting to turn them off). At least it does not add a bunch of services and such. I have had many, many problems with software doing far worse to my system, to the point where I rarely install anything new because it is such a hassle to find and fix the damage, which can be hidden using so many methods (services, explorer add-in's, registry startup's, ini file startup's, etc). I only decided to install a new browser because a few web sites are demanding I "upgrade" my current browser.
One of the reasons I settled on Opera was because it appeared to be better about that sort of thing. And so far, it does seem better than a lot of software I've dealt with, but it could still use improvement: Nothing beyond the program that you are actively running should ever run (with regards to a given program's installation), and everything the program does (particularly automatic updates) should be clear and configurable.
Anyway, thank you again