I have a similar situation with my family. Some random things I use…
I use glutinous (aka sticky/sweet) rice flour (a misnomer, it contains no gluten) to make white or brown sauces and gravy. Mochiko brand, from Japan, I find less gritty (or not gritty at all). I use it to make roux and bechamel, since it will brown similarly to wheat flour (you may have to adjust flour to butter ratios). I use this for GF Thanksgiving gravy and for creamed spinach and you almost can’t tell the difference. One drawback is it thins out when reheated or overheated, but if I want to reheat or if it seems thin, I’ll add a corn or tapioca starch slurry to help.
I also like tapioca starch/flour to dredge meat before pan frying or even deep frying. I use it in Chicken Piccata for instance, to make it GF. I’ve used tapioca flour as a binder in meat loaf and meat balls as well. (Not vegetarian, I realize.)
Claudia Roden’s Whole Orange Almond Cake is a fantastic recipe—easy, a crowd pleaser, and has no flour at all. https://cooking.nytimes.com/recipes/3251-claudia-rodens-orange-and-almond-cake
Another fave is the America’s Test Kitchen southern style corn bread recipe. I just leave out the white flour it calls for and it comes out great.
In general, my favorite replacements/alternates are white rice flour, sweet/glutinous rice flour, and tapioca starch. For bread crumbs, I dry out and crush GF bread. But in general, I agree with others who say it’s rarely as successful to try to recreate wheat recipes than to use one that never had wheat.
For a GF free soy sauce look for tamari, it’s made without wheat. It’s Japanese style (darker than Chinese), but I think that some Chinese brands are coming out with GF soy sauces now too. Golden Boy fish sauce is my favorite brand and it contains nothing but anchovies, salt and water.
I’ve found it a an interesting journey. I’ve expanded my repertoire and techniques. I’ve discovered that many older recipes, (18th c, turn of the 19th c, or depression era) use alternate flours or eggs to leaven much more than you’d expect and those can be a rich source. Also, old Italian or Spanish baking often used almond flour and no wheat; another realm of exploration. And of course, there are quite a few extremely helpful GF cooking websites/blogs out there.