Here is my initial logo idea I came up with, after reviewing your brief and comments: #14. I wanted the logo to be both fun and professional at the same time, while conforming to your requests. I also designed it with the intention of making something that would look awesome on shirts, hats, etc.
Let me if you want to see any changes/revisions, as I would be happy to work back and forth with you to get this exactly how you want it.
And here is a distressed/grunge design, which could give t-shirts a really cool vintage feel. Oh, and I also made "XPRESS" bigger and more noticeable for a bit better balance... #15
Example 15 You are on the right track. Can you give us some designs with Bubbles all CAPS? Also if you could give us the current design on 15 with different arrangement of colors.