All Signs Point Toward Needing to Read the Signs

How should the text of signs be formatted in a fiction manuscript? I've seen it in all caps but I am not sure if this is correct. For example -They drove past the rickety WELCOME TO TULSA sign.

You are over-thinking this. If you desperately want to be correct, you could look it up in the Chicago Manual of Style, which is what most people use. But most editors will look benignly on however you format such a thing-- as long as it's clear what's the text of the sign and what isn't, it's fine. The copyeditor will adjust it to the house style later in the process.

In the days of yore, when email was exciting, there were some who'd always advise us to send partials with SASEs. Part of the thinking behind this was to control who got to see your MS. Has that culture of mailing queries and partials completely gone away now?

Of course, I realize that - in theory - once the MS is out of your door, it can always be copied and leak out (say, if you're Dan Brown or J. K. Rowling). But how does the author know her MS was read and rejected? That it didn't drown under the giant swells of other partials?

It seems like you have more than one question.

If one of your questions is "How do I know my manuscript won't be copied or stolen or something?", please refer to the pythons.

If one of your questions is, "Do people still want a partial MS and an SASE?", please refer to individual publishers' submission guidelines.

But to "But how does the author know her MS was read and rejected? That it didn't drown under the giant swells of other partials?", the answer is a question: Did you submit your manuscript to a publishing house that accepts slush? If yes, then assume it was read and rejected. If no, then assume it drowned.