I did an internship with paypal for my senior management class last semester and i was with them for 6 months (Oct. 2009-Apr.2010) and can prolly provide some tips for not getting red flagged and or getting your money back quicker. Here is a little but of what i did. I was one of the interns who dealt with Account Management, Payment transfers, and New accounts. It was definitely a fun internship and im hoping to get a job with them.

First things first, here are a few ways to not have your money held or your account limited.
-Use more than one paypal account.
-If you have more than one bank account use different bank accounts for different paypals
-As soon as payments go threw immediately transfer to bank account (the longer you hold money in your paypal account the better chance of getting red flagged)
-Paypal is worried about the money being held in their paypal accounts, not necissarily the outflow of it
-Do not receive payments as a gift. (Receiving numerous gifts draws attention to your account) i know this can be a hassle but if your legit you will have all the proof you need to keep your money
-Make sure everyone explains what the service is theirs paying for

Here are some tips for for getting your money back if paypal is holding it:
-If your running a lobby record your livestreams, and save all transactions you have
-If your selling Jtags and KVs, all transactions MUST MUST MUST be saved because anything over $200 will be specially documented to paypal
-Save any emails or AIM regarding payments or confirmation of payments
-Constantly contact paypal, either through phone or email. (Phone is best)

The reason that paypal holds your money is because so many people have paypal they have a hard time looking through every account and cant monitor it effectively, so they put limits on accounts so they dont have to constantly monitor them. The process is bullshit for sure but it is the most legit way of sending ans receiving money. Hope the post helped if you have any questions PMs are always welcome