You could always have your quilts 'chipped' so you can find them or trace them. That is probably too pricey though for most of us.
As for security, know the venue. Yes county and state fairs may not have the best security but if they hang the quilts high enough they will be OK. Me, I'd want to be there when they were hung and taken down.
Self taught isn't necessarily a negative thing. You may well have stepped out of your 'box' quicker than others.
Usually guild shows are much more sensitive to this issue as they have the white glove quilters to even keep visitors from handling the quilts.