What does it look like I have?

Originally Posted by Zangief

Can you explain to me why a really good player would play Kx or better that way?

To avoid spewing with a very live flush draw out (since an aggro player will make it difficult to figure out where you're at on the flop, but will more often fall in line on the turn.) By playing a turn you can screw the draw and get a better feel for where you're at. Also, the lead looks like a stupid stab at the pot, so you'll get raised by aggro players who think you're full of shit.

I'm not saying they would always play Kx like this, but it certainly would be a line to consider.

Same reason Bruson in SS says to leads sets into the PFR, it often goes like this:

You: Donk
PFR: "I still have a big pair" or "I still have 2 cards damnit" or "How dare you donk me!" Raise!
You: Re-raise
PFR: Fuck, I'm pot-struck.

Originally Posted by Zangief

Also, what does "You're too tight to float" mean?

I doubt you call this flop in this game with very few outs (4 or less) intending to steal the pot on a later street with a bluff (aka floating.)