Going down the list
1) looks like generic shoulder plane, could be almost anything, probably not worth much
2) vintage style rabbiting spokeshave. Without a maker mark, could be almost anything. Could be valuable.
3) kitt center finder, cheap
4) looks to be a hock kit plane, I wouldnt call it valuable, but they are quality.
5) generic super vintage smoothing plane; can be found pretty cheap at flea markets. Probably just a show piece (thats what I use them for)
6) irwin spokeshave, good quality, not super expensive
7) bailey #18 plane, not expensive.
8) stanley handyman was the budget tool line, but that thing looks pretty solid to me.
9) hock kit plane, not valuable, especially while damaged like that.
10) couple of sargent planes, not really valuable. Hard to tell models by the front shot
11) irwin block planes. Those are pretty pricey new, and they look pretty new lol
All in all, these look mostly quality. The wooden planes are probably not the greatest in their condition, but the irons should absolutely be salvaged. Hock blades are fantastic. Sargent and irwin are respectable brands. This would be such a welcome addition to any woodworkers shop, and frankly, unless you paid too much (doubt it by the sounds of things), id say you have a very respectable collection now.
Direct answers ->
1) Stanley handyman is the "budget line"
2) Irwin (record here), bailey, hock, and sargent are quality tools.
3) Not ALWAYS... but generally tools that are "blue" like that are irwin
4) purely for the fact the one is for sure a hock kit, I'd argue the others are as well; dont believe they are handmade. The super old beat up vintage one IS, but that things 100+ years old probably lol
5) the "center square" is for round stock. It works identically to the photograph Im going to link.
congrats on the tool haul, Im quite jealous of some of those!