What's the best way to outsource order processing w/PayPal

What is the best way to outsource order processing (dropship) with PayPal? PayPal really, really sucks. However, one of my vendors only accepts PayPal. I tried to create an additional user for my assistant, however, he wasn't able to go through the checkout process with that username. PayPal only accepts email addresses during checkout! I called PayPal and spoke to Christine and she recommended setting up a different PayPal account. So I had to set up a whole new PayPal account and customize the checkout page again. I gave my assistant the email & password. He was able to process 2 orders, but on the 3rd order, it blocked him and presented a security check! I called PayPal again and spoke to Tina who said the only way to bypass the 'security check' is to link a bank account, add PayPal debit card, or apply for PayPal credit. I tried to apply to PayPal credit, but it is only offered during the checkout process! You can't apply for it from within your account! WTF? So I applied for PayPal debit. Now, I'm getting random emails from PayPal saying my transaction was declined, even though I did not initiate a transaction and my assistant did not process orders either, and there is no record of a declined transaction in the account transactions either. I would ideally like to set spending limits for my assistant, but PayPal does not offer that feature. So I manually fund the order processing account from my original personal account which has the bank account linked. I can not link the bank account to the new order processing account because PayPal won't even let you link a bank account to two PayPal accounts, plus that would defeat the purpose of limiting spending. I do not wish to have a hacker break into my PayPal account and withdraw all my bank money and send it somewhere (because my assistant would never steal from me - but they do keep passwords insecurely). So how do other people outsource their vendor payments that use PayPal?