The I: Thanks a lot for your worries. They show, in my eyes, that you are a good dominant. You are thoughtful. Questioning yourself means that it is unlikely that you will hurt a submissive out of ignorance. You seem to me caring, not focussed only on your own fun but someone who wants to have a real partner, even if you´d like to bind her, spank her, humiliate her... whatever it is that you like to do... Someone thinking of the partner as much as of himself, or even a little more will not act out of any supressed fear, it shows indeed a lot of respect for your partner if you try to find the perfect way for both of you to live out your kinks.
Forgetting to show dominance sometimes...Is also a sign that you do not really want to hurt your partner but want her to have as much fun with you as you have with her and as long as you realize that feeling dominated makes part of the deal for her...
Its not important if you move a little slower in the beginning and test the limits slowly instead of crossing a boarder too early. you do not always have to reach the limits of your sub to make her happy.

Actually this is something I did not realize until recently as my new master and I were experimenting a lot. He went a lot slower than I wished it. By now he knows how far he can go and I realized that this moving slow was not only to his best but also to my best.
I trust him deeply. I know that he will never hurt me conciously and that he has enough selfcontrol that it is very unlikely that he will hurt me unconciously. He reaches my limits now, from time to time scratching along the border. ;-)
Fact is we are both young as well (I´m only two years your senior) , just starting off in the lifestyle and both are questioning what we do, what we like. And all the thinking makes us better as it gives us a better understanding of ourselves and each other.

Good luck to you, youngling.
Deigja