Rusty crankshaft, and cylinder head

clean it up with fine grinding paste and a lace or a strip of 1200 or 1400 wet n dry dipped in diesel

it'll be fine

dents don't matter its raised bits that gouge out the bearings

if its is confined to the area around the hole...no problem its a big fat journal
race bearing would be full groove i.e you can have a section of that journal unsupported.... so a bit that isn't supported no problem it will be full of oil


if pitting covers the whole width of the main journal there is a problem and a regrind of the mains is in order.

Dave