Bread – To make Gluten free pancakes, can I just substitute regular flour with Gluten free flour

Gluten free bread recipes are hard to get right, and maybe won't function with kneading per hand (there was a question about non-rising gluten free bread yesterday). You are much better off with an existing gluten-free bread recipe. Pick one which you know to be good, and prepare the dough as usual. Follow the recipe which is described here from the "Take the dough and flatten it out a little" sentence on, using your known good gluten-free dough instead of the one described here.

I don't know what would be the best substitute for the soaked wheat, experiment with soaked grains or myabe something else which gives a slight crunch (sunflower seeds, almond pieces - don't soak these).

I would go out an buy some.

Dough textures for gluten-free breads are fragile and the result of extensive testing with various non-wheat flours (at least, good ones like Serious Eats are). None of the other flours you have available will have the same water absorbsion or starch content which rice flour does. If you substitute, you'd have to make the recipe several times in order to recalibrate it.

Besides, rice flour is generally pretty useful if cooking for someone who can't eat gluten. So you'll use the rest of it. And if you can find it in a bulk foods store, it's quite cheap.