I just keep kibble out for them. Spooky overeats; Nermal is content with a token bite when he comes in. It's hard to accommodate two radically different creatures.
So far, so good. The screen door has only been assaulted twice, and only one quick squirt for emphasis. Cat's dry and I am uninjured, so day one wasn't as bad as expected.
Sounds like you've got it all under control, Roger. Glad to hear it!
The indoor/outdoor thing is always tough with cats. I find each of my cats is different: Some cats will rip every window screen out, trying to escape to outdoors, and some will never even seem to notice there IS an outdoors.
They do, in fact, now make those underground radio fences for cats. They're pricey, however, around $200 (yikes!). We have one of these for our 3 dogs, and it's been Wonderful!
Oh, I also leave food out at all times for our cats, and have always done so.