Hello, and welcome to Wikkii!
I'm very happy to hear that you've moved from Wikia to Wikkii, because this site doesn't make constant changes that disrupt your wiki, unlike Wikia, and you have more control over your wiki at Wikkii. I've also recently moved from Wikia to Wikkii, so I understand what things are like for you.
At this moment, Wikkii doesn't support rich text editing for farmer wikis, I'm afraid. You can apply for advanced hosting if that is your wish, which requires more technical knowledge, but gives you even more control over your wiki in return.
Literally, the only two restrictions under advanced hosting are that you must include an ad banner for logged-out users, and a "Hosted by Wikkii" button towards the end of each page. My wiki currently doesn't use advanced hosting, but you might be interested in it if the farmer system isn't enough for you.
Thanks, and good luck with your wiki!