I have now ordered a safe to keep all my money, passport and bank cards inside whilst I’m with a client.
Perhaps better not to store everything in one place?
If you have any funds in PayPal, transfer them to your bank account as a precaution in case PayPal decides to close your account.
But as far as I'm aware, even if your PayPal is empty, you're still liable if the client reports the £100. PayPal will refund them and seek to recover the funds from you.
Take a look at the deposits thread:
https://saafe.info/main/questions-and-answers/deposits/(Recently, I read through 30+ pages of it, it was educational. You can find some ideas there.)
I’m wondering if his plan was to gradually take small payments from my bank and hope I didn’t notice, and do this over a long period of time…
Maybe he thought that smaller amounts won't trigger automatic fraud checks by the bank?