Hi, I have many engine fixes I would like to contribute.
Where can I do this? Should I just commit directly to the repository?

I have many multi-touch bugs I have fixed as well as some CocosDenshion fixes

Hi Kelvin, I have been submitting my changes to the forum. You can attach files to the postings, so maybe just post a zip of the files you changed?

https://github.com/cocos2d/cocos2d-x-for-xna/issues

I have started the task of pulling issues out of forum posts and registering them in the issue tracker.