I can't help but think that those drainage channels might or will get clogged at one point including the weep holes.
Your instincts are correct. Additionally, in Houston, wherever there's moisture without sunlight, you get mildew. Mildew in the pocket and mildew inside the mainframe. Not good.
Also, the opening part of the window did not feel tight when closed. I was able to move it slightly back and forth , up and down.
This is called "slop" which just means that the manufacturing tolerances are very loose, which results in a high Air Leakage rating.
on the installation part he said they do not use any minimum expanding foam when they put in the window. The reason for that is because the space in between walls is there to help the house 'breath'.
As others have already said, this is ignorance on display. It's really just another way of saying that a house needs to leak air. Conditioned air needs to be kept inside, and unconditioned air needs to be kept outside - always. On newer houses that are built to be extremely airtight, fresh air is indeed brought indoors, but on on a controlled & conditioned basis - not by allowing the air to infiltrate around the perimeter of the windows. Again, most window salespeople (in Texas at least) know very little about windows and proper installation.
The NT Executive is a good option for a mid-level window, as is the NT Energy Master.