1) No checksum, but usually on old chips(late 70s, early 80s) the rom bits are very visible as you can see. If there are errors in it, it's easy to fix during visual verification.

2) Don't know until you try. But SH1 is a 90s chip, which means the chip die is much more compact and rom bits will not be as visible.
Also, how much internal ROM does Atlanta have? 32KB? that's more than a quarter million bits, a lot of work.

It's better to figure out a way to dump these chips electronically. Actually, UCOM-4 can be dumped electronically too, it's just difficult.