3500 blocks in 1 hour. 
Too many people digging, that is the disadvantage for the later. We decided to restart the block and run the Explorer again within 1 hour
What about those that found blocks on original chain? You will compensate on the new chain for their time and effort, the early adopters and believers of your technology? You should pay out anything below block 3500 to those who send you wallet file of old chain.
yes, I have the same opinion, devs should compensate
Devs absolutely must compensate if the project is to be taken seriously. It's okay to relaunch if there's a problem, but you cannot penalize early adopters. Even if one person got 100 blocks, they should be paid. Ask for their private key, verify their balance on old chain up to block 3500, and pay them.
Pay it out of devs premine to show they take responsibility for errors, and show they are committed to project.