$3.40: Too loose to respect a preflop raise

[vowels]

Sorry in advance for the paragraph form of this post. I haven't figured out the hand converter yet.

I was just 6 handed in a $3.40 STT on pokerstars. BB and I are about tied for 2nd with $2500 in chips. With blinds at 25/50, I pick up AKo in middle position and raise it up to 5 times the BB, to $250. I get two callers, the button and the BB. Flop comes AJ6, all spades. BB bets $150 and I raise it to $700, trying to make him pay to draw to a flush. Button folds, BB calls, turn comes another ace and I move all in, thinking he either has a lower pocket pair or the last ace with a weaker kicker, though I was worried about AJ. But mostly I felt alright because a lot of people at this level will call with junk or a flush draw here. BB calls and turns over 9-6 of spades.

Bwuh. He called a 5BB preflop raise with 96 of spades? How do I defend against this?

It's idiotic, but also dangerous because it makes me wonder if I should just start peddling the nuts, which I'd think is a little too passive, even at this level. Plus, the larger question, if I'm in 2nd, 6 handed at a loose table, should I just fold AK here? AK is an underdog against any pair and only 60-40, 65-35, against any random hand. If I'm decent in chips at a loose table, and think my chances of making the money are better than, say, 50%, should I really commit a lot of chips with this hand? I guess I could come in cheaply and try to hit the flop big, but that seems like a chip drain with 5 callers at a loose table.