Bob, I think you're a great admin, and it's wonderful you're accepting of feedback.
I've observed one of your F1's before, and I think you have a way with people that shows you're capable of handling big problems in a reserved, comfortable way.
You display a maturity - as only further indicated by your desire to accept feedback and grow as a person and staff member - that very few actually hold when it comes to it. It takes patience and a certain amount of desire to better yourself when it comes to accepting constructive criticism.
There are very few negatives, and we'll try to keep this brief. I think you do need more experience managing the role before you apply for the next one up. Alongside that, I'd work on your approach to embracing the full team and try to remember that you are in a team. If you need help, there's no shame in accepting help. I know you've done it before, but just remember that we're all in this together.
Thank you for applying for this role, friend-o.