Another year, another RA offer...

So I emailed one of the prospective graduate students to make an offer. I am so afraid of what happened last year (where a student accepted- filled out paperwork & everything, then backed out in April). This time I have other potential students, but I am just nervous about the whole thing. Then, I am also worried that this student will accept, show up, and be a total disaster. I guess this is always a risk with RAs, but I have so few opportunities to do this, that I want things to go well- especially after this year has essentially been wasted. Ugh.