I looked at my words list of when they will appear again and some aren't for two weeks and I don't feel like I know it 100% yet. I know on memrise you are quizzed more often even if you got it right. I even change the retention rate to 97%. Is this frequent enough?

I hope I haven't totally misunderstood this tool that I've been using for a few years now, but I believe that if you continue skrittering past all your due items, the items that you'll do will be the ones due to become due. I.e, you'll review them sooner if you just do more Skrittering.

Changing the retention rate will only change how words will be rescheduled for future reviews. In any case, Skritter has a bias for learning many words quickly, not for learning everything that you have already added. This subtle difference means that Skritter would rather throw more words into your review pile because you will naturally learn some of them faster than others, and it doesn't want you to get stuck bumping your head against a handful of characters. The pool of unknown characters/words that Skritter thinks you should have at any point of time will stabilize, but will be larger than you might expect (double-digits, not single digits). If you can get used to it, your long-run learning rate will be higher than if you insist on perfect knowledge of everything before advancing.