There is nothing stopping you from having multiple accounts, and in fact, it's not a bad idea, just in case one might be unreachable.
As for the Terms of service, etc, for Fosstodon, htey might seem a bit harsh at first glance, but my stream isn't bombarded with NSFW content. If that IS the kind of thing that you're after, then yea, this isn't the place for you. As I said, you can have more than one account.
There is a SDF Mastodon node also, so if you're not into Fosstodon, perhaps it would be a better fit. - I just realized that I have both a Fosstodon and SDF mastodon accounts.
SDF it's self might take a little to explain. But it's kind of a cool place to SSH into. I don't get to as often as I'd like. - And that reminds me that I might want to check my email over there.
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.