No Min/Max contract length?
No max, but you must fight the minimum for that org.
Min, contracts as usual I'd imagine. You should post the 2 different start dates for the 2 different tiers so there's no confusion and DQ's.
I PM'd the 4 new camps that needed to start in Tier 1, and gave them yesterday & today to catch up. All the other camps will be starting tomorrow PM, so I believe the PM would correct what you're worried about.
do we have to fight every reset?
jbear answered exactly as I would have, just make sure you don't fight less than the minimum amount of fights in each org.