that should get you hired at a regional once you get recurrent.

Not actually necessary in order to get hired at a regional, unless you plan to instruct for a while to get current. Probably simpler and faster just to do a FR/IPC, rent an airplane and fly around a little to get your comfort level back.

I would strongly suggest some FTD time with a CFII to get solid on instruments.

You'll need to study the ATP material for interviews. But you will not actually have to retake the written since an expired written is always good at a 121 operation. This assumes you plan on doing your ATP during new-hire training at a regional.

If you wanted to get your ATP part 91 before you apply to regionals then you'd have to take the written again. This would give you a very slight advantage during your new-hire checkride since the evaluator has less flexibility on an ATP ride. I'm not sure it would be worth thousands of dollars, but only you can decide that.

Did you log that time? If so, you will be at risk of having to explain C-130 systems at a regional interview since that is the most complex and recent airplane you've flown. Every regional will have a few ex C-130 types, and some will make sure that guy is at your interview.

Hopefully the wife's job is portable and enough to make up for low regional FO pay.

Yes, just get current. You may or may not need to log a few hundred hours to be competitive at the "better" regionals.

No, you'd need to rack up some recent flight time and network to make some connections.