Welcome to RN artistformerlyknownasargentus

[Mystic Wanderer]

That is a rather long name

Yes, it is. The good thing is, you type out the first three or four letters of someone's name and RN will pop up the full name for you. Click on it, and it's done.  

should I have truncated my name to the more known form?   If I should be zapped and reregistered, just say.

You'll have to ask a MOD, but personally, I see no reason to change it if that's the name you want.