I'm all for crypto being anonymous, distributed, buyer beware. Unfortunately, as soon as it touches fiat currency the feds have other ideas.

If you're a US citizen then you're opening yourself and any US users up to the issues that localbitcoins had. This includes users being charged with money laundering and unlicensed money exchange services.  You really need some good crypto legal advice to keep yourself from running into issues. The gov won't care if it's only a hobby project.

Not trying to be a downer, I firmly believe the more devs working in crypto the better. However, I've been around enough to know that any service needs a legal review before it goes live.  If you aren't friends with any lawyers look around. I had one that I could pitch projects to and he'd gladly listen and tell me what would be needed to launch without any charge. He would only charge if I then asked him to do work. He said it was a nice change from the typical business stuff he did.