Instead of using oil you can use butter this works just as well as oil sometimes even better .One bad thing is butter can be worse for your health then oil .Also there are oil sustitutes made out there.
no
no
yes
Yes, you can use 75w-90 gear oil instead of SAE 90 gear oil
If for baking, you can use sunflower oil.
Yes, you can. :)
Yes
Cork grease. :)
Sure, but it is way more expensive that heating oil.
Yes. Yes you can.
Probably, but it depends on the recipe.
Yes you can.