Or if we did use paypal what if I put down, "repayment for personal loan. Non-refundable." And I wrote an email saying, "my name is.... sent paypal on this date.... to (your name), and I understand this is non reversible", Not even Paypal would allow that to be reversible or would they?
Of course Paypal would allow to reverse that. Its enough that the account owner claims that someone else logged into his account and did the transfer. Description is irrelevant, as there is no proof that the real owner of the Paypal account sent the transfer. It's enough the real owner claims "it wasn't me, but someone cracked into my account (by a key-logger, looking at the password from behind his back, or whatever).
About buying Bitcoin: what's wrong for you with sending a bank transfer?