One question:

While I'm able to make patches in form of icons, I have unfortunately no programming skills.

Converting existing patches which have no settings page seems to be quite easy with your skript (not tried it yet, will do on weekend).

But the part with the settings page is not clear to me and further more, how to create rpms.

So who is meant to make these? The patch creators? you? or whoever wants to?

In the end, I still think the best would be merging Prepatch and Patchmanger. But I don't know if both parties are willing to, even so you've already written, that you are.