1. Yes, you would pay 1,900 sats
2. You can calculate a hashprice for bid / 21 TH/s and compare to what you could earn in a "trad" mining pool

However, since I am adding bonus hashrate that tilts the odds for the block party, there isn't an easy way to compare to the block party's value..

(hence the auction!)

3. You pay your winning bid, you will get your fair % of reward if we find a block

I email everyone before the party starts mining on Friday.