"I just want to confirm: Fried foods are OK when they are NOT fried in the same oil as wheat stuff, and NOT ok when they are friend in the same oil as wheat stuff?"

Yeah, fry some stuff at home and look at the results (its fun!).

The first time you fry some fish in some oil and then fry some french fries in the same oil you'll know exactly what I'm talkin about. It does not require gluten issues to see little specs of burnt fish-coating all over your fries. Its crunchy, sometimes tasty, and not overly gross, so most non-GF don't much care. If people complain the fries taste/smell like fish or chicken, then its a cheap place and you're probably going to get sick.

Its not a water/oil polar/non-polar extraction like in o-chem class or something like that, or even microscopic contamination from using the same tools or whatever, its just big ole chunks of batter flaking/falling off and then physically happening to land on the next thing thats fried, like maybe your "GF" fries.

"I used to get french fries and they'd be hit or miss"

Culvers, well, at least the local one, never ever uses the same fryer or same fryer oil to make fish/chicken and fries, therefore their fries are pristinely pure nothing but veg oil and potato. Frankly I like french fries that taste like potato instead of chicken/fish fry night, so I prefer them too aside from my son's diet issues. On the other hand I can personally verify the deli I worked at as a kid (a long time ago) only had one fryer, so our fries got a little fried chicken batter/spice and fried fish flavoring. And the local Burger King is the same deal its all mixed together, ick.

"somebody told me fried stuff _always_ has gluten, which I didn't really understand, but I mean, I'm not a cook"

Kinda true but also kinda false. The absolutely cheapest way to get a crispy battered crust on a fried food is wheat. So guess what the only breading choice is on the general market. All non-GF batters are wheat based because its cheap. If you're willing to pay like 5 cents per serving more you can use a variety of GF rice flour / corn flour / who knows what flours, to make a crispy batter at home. We do home fish fry day (outside) a couple times per year. Much like all non-specifically-GF frozen baked meats (lots of tap dancing around just calling them mcnuggets or battered fish sticks/filets) contain wheat flour, but that doesn't mean the Ians GF nugget/stick products don't exist.

Also as a guy who does a heck of a lot of cooking because I like to, frying does not equal breaded meat. I can fry sausages or hamburgers or homemade hand sliced potatoes all day and no breading means no wheat. On the other hand cross contamination could be an issue, so I can't fry wheat pancakes on the frying pan and then use the same pan without through cleaning to fry my GF son an "GF" egg. I sure as heck can't use the same spatula. This kind of thing over the past decade makes the whole family GF even though only my son has a medical diagnosis... I only eat gluten containing junk food at work or when going out alone.

"don't go to restaurants that serve steak very often"

Well yeah OK. Now realize there are $300/plate steakhouses which I do enjoy visiting on a semi-regular basis but we also go to a lot of $15/plate places. In other words you can go to the "Texas Roadhouse" chain about 20 times as often as some place with a french name you can't pronounce and a wine list that needs reservations.

I/we have had pretty good luck at buffets and they're pretty cheap? Fruit is nature's junk food, you can get fat eating bag after bag of grapes but I don't think its biologically possible to get fat eating iceberg lettuce and celery. So put lots of fruits on your "salad bar salad" if you're hungry.

Sushi, hold the (wheat based) soy sauce and we've had good luck, then again they've gotten "trendy" such that a roll is now like $10. Also Sushi is pure binary love/hate either you'd eat it all day if permitted or be totally grossed out.

We've had good luck with boiled seafood, hold the garlic bread, but lobster can get expensive in some parts of the country.