Was this guy a scammer?

You can always rebuild rep. If the key was part of the deal put it up, if not then don't.

That sounds mostly like a scam

I would be wary of people who type at the speed of light.

highest rep always delivers last. If I were you, I would tell him to bite me and I'll find someone else that will not force me to give a key first.

Clearly a wizard. Watch out!

He's only a scammer if he scammed or tried to scam someone. Feeling like it was a scam doesn't make it one. Also, rep comments don't matter and the little you have wouldn't be confidence boosting anyway. :P

Some traders go by their 'rules'. The only rule is only trade with people you feel comfortable with trading and don't be trusting of strangers. None of that "Well, it all depends on who's rep was higher" crap. Sometimes one of the most profit-making moves you can do in a trade is to walk away. You'll feel better not dealing with an asshole, than if you had dealt with them and gotten exactly what you wanted after enduring their idiocy.

Just 2 cents. :)

If you are ever in doubt about a trade or a trader, just don't do it. Its that simple. Find some trustworthy, polite traders to do business with instead. I've fared quite well on ST.

higher rep goes last, and keys go first, in that order!

As a general rule, don't trade with anyone who types profanities. Seriously do you really want to trade with someone who can't even keep his cool online? Plus they are mostly scammers anyway.