Does not involve paypal at all
Willing to pay your ebay fee via a bug i discovered in their system
Will go first if you are trusted
will require your login and pass to get it dont
You are safe as i do not need your email or phone number access
Asking for 50% of your total fee price in BTC
No. This is not safe. You are asking for their ebay login details which means that there is a high likelihood that you are going to scam by doing something with someone's ebay profile, or extort money from them by withholding their ebay account.
Even if this is legit(unlikely, since why would you be the only one that happened to know this exploit?), ebay will track you down and demand payment because it is after all, done on the customer's account and can be traced back to them.
Plus the fact that you're a newbie... It doesn't look good at all, man.