That was iodine to disinfect before surgery.
What irks me is when she wakes up and starts to Vlog, and we can clearly see that she's not wearing pjammas. It just seems so personal to me; I mean, for the love of Pete, get dressed and then Vlog!
I got that; I loved that show =)
It's not impossible, but unlikely. Remission can happen without surgery. She is relatively healthy besides the cancer. She doesn't smoke or drink, or have other underlining conditions that we're aware of, so yes, it could happen, but as I said, it's unlikely.
She eats when they're out; I think she's just a picky eater. She likes junk food. If she does eat smaller amounts, it could be because her bowel movements are not pleasant, and so she thinks that if she eats smaller amounts that she won't have to deal with too much blood. Just a theory.