Yep, that'll work. I pulled my tube a little further up in it, but if you want to see the bubbles, you might leave it around there. Or you could put it in the bottom section, for a greater chance of seeing the bubbles.
I've not had a problem with that. The suction's not that strong. You'd have to have the tube sticking down into the mixture on your generator for that to happen, i imagine, and then you wouldn't get the gas anyhow. The gas separator is there as a safeguard. I personally have had nothing but gas go into the separator... never any kind of liquid from the generator.
If not. You could run the line down a couple of inches below the intake and let the natural curve(from being curled up in a bag) of the airline, curve under the intake.
You'll see bubbles come out of the line, then sucked into the intake.