What do you consider spyware? Does Google track you through it? Of course. And, by "you", I mean "you" as a demographic. They are looking at your browsing behavior, not your credit card information or anything. This really shouldn't concern you, as they are already tracking your habits through Google.com, Gmail, Chrome, etc. There is an option to disable their snooping under "Privacy" if it really concerns you.
You can see PageRank through a wide variety of add-ons and extensions. Personally, I really like SEOBook.com's firefox add-on, or SEO for Chrome. They both show a wide variety of metrics that give a clearer picture than just PR.
I installed the toolbar just to check it out; it looks like it could be useful for a lot of things.