I am not sure,I've been a seller and buyer for nearly 2 years... I got 6 emails at a time from Paypal that the buyer had filed a dispute... Still can receive & send funds...
Yes, if your account happens to be deemed a problematic one and there are a high number of chargebacks and disputes, your account can be closed and your use of PayPal will be denied.
Sounds you counter a lot of problems How many disputes do you get per month? I just try to keep safe of my account
Yes, if you keep on getting too many disputes PayPal might limit your account for fraud activities and will also ask for some documents that you have to sent them.
Depends on how many you have ! If you get only a few disputes per week, why not - give a refund and continue your work