Non-sanctioned (aka Backyard, Shadetree, etc) events can be frustrating because they tend to be run a lot more loosely than a sanctioned (Pro) contest. The reason you may not have gotten answers to your questions is the organizers may not know the answers yet! It isn't unusual for things to change as late as the day of the contest for unsanctioned events.
Stability and predictability at a contest is a big part of why folks do sanctioned shows. My best advice for non-sanctioned events is to use the phone (email doesn't have urgency for most people, and it's not 100% reliable) to call the organizer, arrive as early as possible and be prepared for anything. Remember, even if there is a KCBS contest at the same event that doesn't mean the non-sanctioned contest will be operating by KCBS rules, or even that the KCBS scoring system will be used for the Backyard Division.
Don't assume anything until you see it in writing, and even then be prepared for the story to change at the last minute. Be sure to have fun while you're at it, because if you take a non-sanctioned contest too seriously it can drive you crazy!