Trying TKTS for the first time - do they hold back better seats until later?

I'd like to try to get Phantom tickets at TKTS tomorrow in order to get the best seats I can afford to see Sara Jean Ford before she leaves. How fast does the line move? How long has it been lately? Do Phantom tickets go fast there? Should I get in line as soon as my bus arrives (probably 10 am or a little earlier), or wait a little while, in case they save the better tickets until closer to curtain time in order to maximize premium ticket sales? Or are all the good Saturday matinee tickets usually gone by Saturday morning since people can buy them at the South Street Seaport location? If TKTS only has lousy seats in the last few rows of the orchestra, am I obligated to buy them, or can I turn them down and go to the box office to see if any better seats were released for the discount codes? (I mean, maybe I can, but would it be way too rude? If it is, maybe I should try the box office first. And yes, I know there are other shows worth seeing... I'd love to see "Follies"... but I'd have another chance to see that in the coming weeks, while this is my last chance to see Sara Jean Ford.)

Also, if you want 2 tickets, do you have to buy 2 seats next to each other, or would TKTS let you get two individual tickets if you can get better seats that way? Would they avoid selling a pair of tickets if it happens to be next to another available pair, saving the seats for a group of 4, the way Telecharge seems to do?

Sorry if these are dumb questions (and too many of them). I figure maybe I'm better off getting flamed for posting dumb questions online instead of holding up the line to ask dumb questions tomorrow. Generally, I'd appreciate some advice for my first attempt at TKTS, and I'd like to know if I stand a decent chance of getting seats in the first half of the orchestra or the front mezzanine. Thanks!

TKTS does not hold back seats. That said, the box offices can send and pull back seats from TKTS all day long. The only thing they can't do is change the discount percentage during the day. If tickets start at 25% off, 40% or 50% that won't change during the day.
TKTS may receiving better seats from the box office after you buy yours, but TKTS will always sell you the best they have.

I know TKTS will sell single seats. I don't know about buying two singles vs two together, except everytime time I've seen two "Singles" they have been far aisles. Two would probably be more centered and IMHO better.