food

Pickled turnips could be something. I love them with falafel but they would be great in a picke pot. Also your onion idea sounds good too! Maybe some of those tiny onions whole for a fun pop. And yeah keep the salt ratio correct by adding over time and you should be set. Eternal pickle pot!

Yeah it's probably fine. On my funky batch, the head was sitting around a bit before I used it. Looked fine but just slightly less crispy. The sauerkraut smelled not totally unlike kimchi, less strong though, or maybe you could say there was a hint of farts and beer or something like that. Not exactly unpleasant, just unusual. My best guess is that some yeast started to do its thing but was then snuffed out by the acid, but idk I'm not an expert.

Edit: There's a brand of salt-fermented pickles here, which for some reason they then put in vinegar (why?), which also has a similar farty smell. Pretty strong actually, not a fan.

Maybe it's just that I'm used to white cabbage sauerkraut, and associate red cabbage with the traditional recipe around here ("Blaukraut"), where you take the fresh shredded red cabbage and boil it very soft, with onions and sugar and often apples. Still the fact that white cabbage is the only sauerkraut you can buy makes me think that white cabbage sauerkraut is pretty universally preferred.

Basically what @Jabril@hexbear.net told you is right: just make it without chili. This is often called white kimchi, if you want the term to throw into search engines to find some recipes.

You can follow any kimchi recipe and just omit chili. Chili comes from western hemisphere so there was at least some period where kimchi was getting made without chili