Questions on BIP-300

Greetings,

I watched this talk and was left with a couple of questions.

1. If miners get fees for what's going on in the side chains, then who will provide resources to validating what's going on in the side chain? Doesn't it need its own miners? And what do those miners get?

2. Why do we need to "improve miner incentives"?

3. When he says we'll copy alts, does he mean we'll transact wrapped alts in sidechains? Or is he speaking of clones that can't be "unwrapped" into the underlying alt?

4. Paul says you can run a turing complete language on this. He also says you can't use BIP-300 sidechains to extract money from people. How do these two statements play together?

Thanks in advance