So my question is why did I set up two seperate services for this?
Unfortunate side effect of buying someone else’s product instead of just making your own.
can I reply to incoming emails from the aliases created in proton pass without them revealing my address?
Yes. It’s called a relay for a reason. When you receive an email it will come from a relay address, not the actual sender. You reply to that relay address and then the other party receives your relay address (alias).
Fair enough.