For best results I recommend following the recipe as it is. White wine vinegar really makes a difference. I wouldn't add brine without adjusting the salt as it will end up overseasoned. Pickle juice is usually vinegar-based anyway. Hope that helps!

I haven't tried it but I don't see why not.

Thank you for posting the recipe.

I don't recommend it sorry. It's a shame because I'd love to be able to use it too. It's too savoury in flavour though and not really silky smooth like store-bought cream cheese. It wouldn't work well at all. Store-bought vegan cream cheese like Tofutti, Violife or Nafsika work brilliantly in the carrot cake. Hope that helps!

Nutritional yeast isn't an active yeast if that makes a difference. It's deactivated. It adds umami/depth of flavour so the recipes will be at their best with it but you could omit it if you wanted to.

I can’t have yeast in my diet right now. Is there any way to still make these butter and cream cheese recipes without it using the nutritional yeast??

This recipe as it is, is very savoury tasting. It's also very slightly grainy. Extra firm or firm tofu also can go a little lumpy and almost curdled looking when baked. I haven't tried it in cheesecake because of that. If you were to try it you would definitely need to omit the dill, and garlic powder etc and I think then if it was an unbaked cheesecake it could work ok with some sweet flavours introduced. I don't think it would do so well in a baked one though.
I do have an amazing baked cheesecake recipe on my website. It gets great feedback and it's always my go-to. You can find it here: https://avirtualvegan.com/vegan-new-york-cheesecake/
And watch this space because I've just developed a ricotta recipe which I think would be perfect for cheesecakes! I'll be sharing it in a few weeks.