1 - Depends on when you registered. You may have been reading anonymously for a while before you registered. If you have proof of being here longer - I'd contact Hubpages directly. Otherwise, you likely get the 3yr accolade on your 3rd anniversary.
2 - Not sure. It happened for me a day or so after it flicked over. However, it may be that if the same IP address is visiting a lot (ie: your own - edits etc are also counted in the numbers) that whilst these are counted, they aren't against the 'total' in the accolades...I'm not a HP staffer, so I'm just quessing.
3 - This one I know!. Mechanical Turks (Program through Amazon) read the hubs, and give them the scores based on...a formula that HP has given them (thats a guess...sorry). Each person will score differently.
4 - Sure, but then what if your hub was viewed by one person/MTurk thing who happened to disagree or be against your views expressed in the hub - eg a homophobic person reviewing a Pro-LGBT hub, or a religious person reviewing an Atheistic hub. It could be badly scored, affecting it's revenue making ability (for the hubber and HP as wel), merely because someone let their own opinions cloud their score.
I'm guessing for most of them...but it's what I can figure