Avoiding abuse is very important, obviously.

My idea was that this would just be a "match-making" service, with most of the traffic taking place out of the Monastery.

The section would be moderated, with the moderator eliminating requests that are clearly not from non-profits. This would be pretty easy to do in most cases.

It would then be up to individual monks from there to choose their projects and verify the status of the agency.

I think this is a great idea - I know many technically inclined people who might like to donate their time and skills but see no way to do so that wouldn't take up way more time than they have.

I would therefore suggest some way that people can get recognition for the hours they put into these community projects - perhaps a web page listing contributions. Mainly for those people who want to demonstrate their charitable time contribution (the self-employed, college applicants, etc.)