dstiles - 8:50 pm on May 18, 2012 (gmt 0)
In general, only one user per IP - two or three if it's a family, maybe a few dozen if it's a company running through a single IP. Doesn't matter about the UA. Why would it matter anyway? Millions of UAs are identical. Given a single IP and multiple UAs within a short time frame, the likelihood is that someone is trying to game the web site - and will get banned if there is any security system on the server.
Google can only know a web site's logs if the site is dumb enough to use GA or is stupid enough to make its logs public. In either case you can discover this and a) block GA (and any G cookies) or b) never visit the web site. If you never use google and block all of G's APIs and scripts then you need not fear G. And, of course, providing you never use G search - or G anything else.
There may appear to be plenty of free proxies but chances are the security-concious sites will be able to detect and block them. Basically, any proxy that is not specifically known to the security system (and is not tagged with an IANA Local IP) should be blocked. There are very few exceptions to that and G is not one of them.
I would say that all of the "precautions" you propose lead to an assumption of trying to game web sites in some way. If your intention is "honourable" you are being far too paranoid about the wrong things. It IS possible to use the internet entirely free of google - I've been doing it for the past few years. I've even stopped buying from sites that insist on G APIs and JS being enabled. How can they track you if you never use them and block all their junk that other web sites throw at you?
What you should be worried about is what you say you are not: ISPs. Some ISPs track your progress, some have been known to use things like Phorm, built on a rootkit by a known exploiter. There are several in operation and little has been done to by-pass them.
And then there are all of the interlinked sites that share cookies - who shouldn't.
And facebook and twitter and linkedin and all the other social sites. Those can be far more dangerous than even G if you are not careful and changing your UA or even IP will not save you there (I use "you" generically and not specifically here).
The list goes on.
If you MUST use fancy avoidance techniques then by all means do so, but do not be surprised when a) you are blocked by a site you really want to visit or b) lose all your information anyway.
One other thing - this is NOT the place to advertise your wares. Even were your idea tenable I doubt anyone would try it based on its prescence here: too much chance of a virus being included. No offence intended to you personally but that's the reason: there is no assurance of a clean tool.
Sgt_Kickaxe - the G+ at the bottom of this page is not at the bottom of this page. I have its JS (and GA's JS) turned off. As I do twitter JS. The only JS I allow on WebmasterWorld is WebmasterWorld. If anything G becomes mandatory on this forum then I will leave.