Yes, there has to be a way to stop people abusing the system because it's bound to happen.
A couple of things occur to me....
is not a reason not to help people in need.
(emphasis mine) It is an inevitability, not a "possibility".
Don't let the vetting process get cumbersome or you'll undo the good you want to do.
"Undo" the good work? Nahhhh, perhaps a cumbersome vetting process will IMPEDE the good, but it won't "undo" the good.
Second, working locally and through people who deal with those in need (such as a local food bank, churches with food pantries, etc.) increases your chances of spotting the leeches and frauds, especially when they talk to each other. (They do where I've worked with charitable organizations.)
Third, online direct one-to-one help with people that you do not know is more prone to being abused than almost anything else that you could do. Face to face works *much* better.
We've got a local food bank in my area that is run by this wonderful elderly woman who swore, over a quarter of a century ago after her husband died, that in his memory nobody in this area would go to bed hungry if she could help it. I work through her. :-) You might want to find someone like that where you live. But be warned, respecting people like this and working with them does tend to lead you to become like them. So don't do it if you want to remain self-centered and ignorant of the needs of people around you.
While I admire the idea of local charity, the OP was about using BTC to facilitate charity/"good deeds", which I'm curious about how that might be accomplished. Most of the folks I meet that are in need of charity do not have a personal computer, and vendors of daily necessities who accept bitcoin and currently rather thin on the ground