CiviCRM Community Forums (archive)

There isn't really of a "suggestion box" for CiviCRM, mainly because there is no army of volunteers sitting around waiting for suggestions. I often wish there was, there are plenty of jobs I could give them. But no, it's just us.

For this reason CiviCRM is referred to as a "Do-ocracy" (aka "scratch your own itch"). As in, "those who do, make it happen."

So let's clarify what you're asking. Is it:

1) You want other people to implement your suggestions, pro-bono.
2) You want to commit your own time and/or money to make the project better, and need help getting started.

If it's the former, I'm afraid that won't fly very far (back to the missing army of volunteers problem). But if it's the latter, I think you'll find this community to be very supportive. You'll be able to get all kinds of help and collaboration with design, coding, and testing your improvements.