Negative balance & bank options

Will keep this short & sweet

I sold something to someone (virtual goods), he initiated an unauthorized payment dispute and I won this claim being told no evidence was found of unauthorized access on his part thus that would be the end of it. Several weeks later though he initiated a chargeback dispute via his credit card company now paypal have told me it's ultimately down to the decision of the card holders credit card company, during this investigation my paypal balance has been put into the negative (-£88.03)

I've googled around for information on this but most posts are from 2006-2008 and policies may have changed since then. So, a few questions -

Can paypal take money from my bank account without my direct permission in order to set my balance back to £0? Or any other fees whatsoever?

If the answer is yes, can I simply tell my bank to decline any paypal related transactions? I am absolutely willing to boycott my paypal account for now and forever, way more trouble than it's worth and while that amount of money doesn't seem like a lot it's mostly the principle. That said, what reason could I give my bank for declining paypal requests? Being honest may seem sketchy to them.

I fully intend to ignore any e-mails requesting money, am I safe to leave as is or should I do as above?

It probably makes a difference given different laws, so note that I'm from the United Kingdom (if wasn't obvious from the currency hehe)

 

I think only US bank accounts can be debited by 3rd parties. The amount is insignificant, they are unlikely to go after you for that sum even though they've refunded the buyer out of their pockets but do note that if you intend to use PayPal's services again, you will have to pay the obliged amount then the management will decide whether to allow you in again or not.