Your welcome to contribute via patch submission on source forge. An active developer will check it and commit it if it is approved. If you contribute regularly then we'll approve you so that you can check in changes yourself.
- how many developers are there
We have several developers who contribute depending on their free time. The number can change from week to week. It can range from a couple to five or six at a time. I will have to check to see how many developers are currently working on it.
Edit: I've looked and so far, we have had 12 contributors to the project.
- is there a road map / do you work from trac?
We do have an internal road map that we are working on that we plan to share, hopefully, in the next few weeks.
- is it possible to commit own ideas?
We welcome the discussion and contribution of ideas to the project. I would encourage you to offer your ideas on the forums first. I'll make sure your post is read by the developers.
You could, technically, simply submit a patch with your ideas without any discussion but letting the developer's know what you have in mind would help.
Edit: Thanks for the inspiration. We're going to add a new forum topic called "Suggested Features" where you can post ideas for features you'd like to see added to the framework