I've been buying BTC from someone over a longer term (a year or so) as I can afford it, and the other day they said that I have $2,000 in my wallet (which was correct). This shocked me, the only thing I ever gave him was an address to send it to, and he's been using the same one the whole time.
Can he keep seeing my balance?
Can he (or anyone) see when I spend it?
Can he (or anyone) here I spend it, as in who gets it from me...?
And when I'm ready, what can I do so that my balance and habits are no longer able to be tracked by him?
Thanks in advance for your time.
Use a new, unused address for every transaction. This way, the counterparty is only aware of that address, rather than all of your activity. This is the proper way to use Bitcoin for both privacy and security reasons.
In terms of security, your private key becomes easier to theoretically crack (like with quantum computers) once you spend from it because it exposes your public key.
But when I send the money to my cousin's wallet, can they follow it there, or can they just see how much I have at any given moment?
They can only see how much is in any given address at any given moment. Whether they can associate any given address
with you is up to you and your privacy habits.
