even using tor here are three ways to track you
Ok thanks, but I am not talking about 1, 2, or 3, in your scenarios.
I am
exclusively talking about tracing out an identity just through the Bitcoin payment itself.
How difficult is it, say, for a regular person or privet investigator (NOT the fbi) to trace out the identity of a person using bitcoin to pay for something?
The bitcoin payment will store, roughly, a date, an older unspent transaction and a destination. Using only this info would be hard to link anything to anyone. But in the real world bitcoin is not an isolated system. When you overlay the information of the blockchain with other data then is when links and relations can be established.
It seems there is some confusion here about my question let me try to be more clear.
If I use the Tor browser or serf of some coffee shops free wifi or whatever so the IP is not at all traceable back to me and make a payment to someone that has no idea who I am, and I do not give any personal information at all, and I make the payment using bitcoin, is there any way to trace out my legal identity only using the information from the bitcoin payment?
Given this case, where you "do not give any personal information at all" and "your IP si not traceable", obvioulsy, you should be pretty safe. But let me state that this conditions are not easy to achieve. Also, past transactions or who sent you the coins could leak information again.