I think it's a nice thing to do. I actually received one last night from a user I'd not have expected to boost anyone other than herself. It was nice to see for sure, and I was sure to leave a comment saying thank you to the user.
With the two dot-points. Yeah, Not deal breakers. They want to maximise their curation hence the 24 hour thing and I agree with not boosting/voting twice.
Let me know how you go with it.