Is Raising on the River with nutflush on paired board -EV

[vandalay]

Here is the hand.

Several hours into your session. tight person raises 4X (800) from EP, called by a semi-loose person, Im on the button with A5 of clubs. (2700 in pot)

Flop Kc, 5(red), 4(spade). check check to me, I bet 1700 pot get called by the loose player, (6100) in pot
turn - 9c - giving me flush draw and low pair. check, check
River is a 4(clubs) giving me a backdoor nut flush.

He bets the 5000, with 20k behind him. I have ~20k as well.

Is raising here -EV?
What hands can you put him on?
What hands can he call a reraise with?
If you do reraise, how much?
If you reraise less than Allin, do you fold to a new reraise (raise to 13k, leaving you 8k behind)

of course, I reraised with my backdoor hand and lost, but that's not the question. I was just thinking (now), that my raise was -EV as there are very few hands he can call with.

AK and a lower flush are the hands he can call with and I win.