I've known of a lot of folks in the past who have done things like you described in this thread. While technically illegal, I doubt that you'll have any issues with selling some handloads to a friend. If you try to make a real business out of this practice, without following the proper legal procedure, I'd expect that you might have problems.
However, although the legal aspect of selling a box of handloads to a friend isn't a huge concern to me, as a matter of practice I wouldn't sell handloads to friends, nor would I be likely to give them to friends to use when I'm not around. When I was younger I had some problems with handloads that I bought from a guy who used to sell them, and it turned me off to handloading for a number of years. Although I'm extremely careful with my quality control when I load for myself, I just don't want to worry about it with my friends' guns, and I don't want to be blamed for a breakage/malfunction in their firearms.
I always offer to teach my friends the things I know about handloading, and I even offer to let them use my equipment with my supervision. I'll also let people shoot my handloads when I'm present.