Hello Lucas, welcome to Discovery! It's nice to see so many players joining our server, as you see that community is generally friendly, just like other places in the Internet.
If your group had problems with RM harassing your traders, that's probably because you broke inRP law about trading restrictions, or were breaking war embargo and traded with Liberty. What IDs you were using, what commodities you traded? I know Rheinland a bit, I could explain it to you and answer any questions you have.
You will get many offers from various factions to join them (shameless promotion: DHC is Rheinland mining and trading corporation with awesome RP background), but if you are almost sure you want to play in Gallia, Gallic Royal Navy definitely needs fresh blood.
Post in Help Requests subforum any questions you have, there are many players who'll gladly help you.