I'm not an expert in this field either. N-400 instructions say the applicant should reside for 3 months in a district or state before applying.
My suggestion for OP is to:
- Come back to the US
- Pick one place for residence, file AR-11, and wait for 3 months.
- File N-400 while living there
- Naturalize while living there
In my opinion, having friend's address doesn't help because USCIS is interested in physical address. If OP lived in RV moving around (no stable address) and now filing from overseas, I cannot see how the residence requirement is fullfiled.