The hand took place in this GPL 6-handed SNG: http://www.globalpokerleague.com/schedule/2016/match-13/

Blinds 100/200/25
Fedor (HJ, 26000) raises to 500 with 4h4d
Kevin MacPhee (BB, 21000) calls with ??

Flop (1250) 4d 3c 9s
Kevin checks
Fedor bets 425
Kevin calls

Turn (2150) 4d 3c 9s 8c
Kevin checks
Fedor bets 2000
Kevin raises to 6000 (leaving ~14,500 behind)
Fedor remarks that Kevin's raise size makes no sense because of how polarized his (Fedor's) range is after betting pot on the turn.

Questions:
1) Which raise size(s) should Kevin be using in this spot?
2) Which hands should Kevin be raising?
3) How should Fedor play his range against this raise size? Against the correct raise size(s)?