Your role would be an independent entity who would have to decide who gets the funds in case of a disagreement.
To make an informed decision, "#3" would need access to at least one of the two involved Paypal accounts, right? This is a risk. I'm pretty sure Paypal doesn't allow this, and it'll instantly raise red flags with Paypal if someone logs in from a different geographical region.
All you have to do is not loosing your private key for that multisig address. You would get 1% of the transferred BTC at the end of the deal.
Chances are 1% of 500$ is not enough to pay the fee to use it, making it useless if fees rise again.
I'm planing on doing this regularly in the region of up to 500$/month, but the first transactions would be of low value (e.g. 50$), to grow confidence.
"To grow confidence" is a very tricky statement, and a great way to plan an exit scam. I'm not saying you are, but it's a red flag to me.
In the expected case you only have to provide your public multisig key once and do nothing besides receiving your 1% share.
To take an informed decision, #3 needs to know the details of the deal, and keep track of it for up to 180 days. That's a lot of work for a maximum of 5$.
Only in case of a dispute you will have to step in.
Say #3 is not involved until the end. How will you provide evidence of the details of the deal?
Reputable is someone with a positive trust score, more than 1 year registered, more than 100 messages and active profile.
Thousands of users fit this description, and I wouldn't trust most of them. You should be much more careful who to trust.
