Hmmm...don't fight the saddle. Some western saddles will put your feet forward, and some will put your heels under your hip. Don't worry either way - both work fine, actually. Some western saddles will tend to force your thighs into a specific angle, and that annoys me. The one we have that does that tends to hurt my legs, maybe because I do
"a bump on the side meant up a level, and a pull on the face meant down a level"
Ask the owners for how they cue her. Western riders don't tend to agree much on cues, or worry about anyone else agreeing with theirs. My mare thinks the cue for "canter" is my squeezing both legs and saying 'Come on, let's go!' - wouldn't win me any points in a show, but my horse understands. Works OK on a trail, but letting her choose her lead isn't always the right solution in an arena.
I know a lot of western horses who have never been ridden in anything but a standard snaffle. Both the lady I took lessons from and the lady who trained my horses are snaffle-only types. Our Appy Trooper will neck rein (and behave) with anything you put in his mouth, as long as you don't mess with his mouth too much. My Arabian mare Mia is slowly learning neck reining - she knows how, actually, but tends to think of it as advice instead of a command. However, she neck reins better with a leveraged bit.
Riding with one hand on the reins still feels unbalanced to me. I often leave my right hand on the horn, because putting it on my leg just feels weird.
The only pants I've ever ridden in are $15.88 Wranglers from Wal-Mart. I've never had a problem with seams rubbing, regardless of saddle type. Maybe because my toes point out 30+ deg or so. Hmmm....
Have fun! We'll expect to see pictures of you riding soon