Okay, I don't know any of the answers, but I'll try to guess, just for the kicks.
1. Nothing.
2. Well, Reti often played blindfolded against masters, so I guess it would be him.
3.I think it's either Reti or Koltanowski. Reti played it a lot, often against masters, but Koltanowski still holds the official world record.
4. I guess it's players who play irregular openings that cannot be played from memory and players who offer draw a lot, thus disrupting concentration.
I think most experts will agree my sources for the answers are impeccable.
1. Alexander Alekhine played blindfold against 26 opponents in Paris in 1924, thus setting a new world record. What was he paid for this record breaking performance ?
2. Which master faced the toughest opposition in a blindfold simul ?
3. According to experts which master was the greatest blindfold chess player ?
4. George Koltanowski said two types of players were most irritating when he gave blindfold exhibitions. What types most irritated him ?
If nobody nails this I will let it run for a couple of days