Read a few of your blogs. Very interesting and informative.
I mostly post on the weight loss fating forum. People on the water fasting forum can sometimes be a bit overly religious for me and sometimes seem pretty close minded about a lot of other things as well.

I wouldn't worry about ketones. Thats goint to be normal if you are burning fat and you dont' want to drink too much water to flush them out. Fact drinking too much water on my last fast think was big reason was so dizzy,lightheaded and got bad fainting feelings even when walking around not just from getting up quick. Blood pressure really goes down on water fast ,you may want to get a monitor.I am thinking to get one next fast probably.
You are taking in no salt and no potassium and drinking too much water will flush it out of your system even faster.Lack of potassium is bad you can start getting bad muscle cramps and the heart is a muscle! yes could be fatal.Lack of sodium can drop blood pressure really really low.
I am pretty sure that cold feeling is also from low blood pressure.

I took some potassium pills when started getting muscle cramps in legs they helped that problem.I maybe should have took some salt pills as well but if didn't force myself to drink 8 to 10 glasses of water a day likely would have been ok on my fast and not had sodium or potassium deficiency problems. Next fast going to try to drink when thirsty as many advice and take salt pill or potassium pill if think need too. Passing out when walking around is not very fun.I didn't but came very close several times. Scary feeling.
I switched to juice on day 31 and did 3 days juice, 2 water and 4 juice to make 40 days total.
The juice fast part was much easier than water,energy was much better, I did light exercise aerobic type on my treadmill slow walk at like 2.8mph and sometimes rode my exercise recumbent bike. I didn't do any weights during water fast but been doing them 3x week sine past fast.This is end of week 5 of my post fast. I started off very overweight, am male, was 260 and am only 5ft 6. I am heavy frame. I hit 217 at end of fast, gained back to 227 highest week or so later and was eating sodium and fair bit of carbs and now at end of 5 weeks holding at around 222/223/224 range. I seem to be able to hold there with my exercise,treadmill or bike 5x week and weights 3x week.
I am also no eating breakfast since fast ,if do eat breakfast type meal then just have brunch.
I also do EAT STOP EAT intermittent fasting twice a week as well. You fast for 24 hour periods twice week.

I would have thought all that would have made me drop more weight but as said seem to be able to hold not lose ,am in plateau or something past week or so.
I may do shorter fast like 20 day .3 juice, 2 water and 4 juice couple more times trying to get to 180 maybe even 160ish for final weight.I don't use bmi I prefer to look at Bodyfat and muscle mass.

Also lot of women in my experience for some reason think men want them to be thin boneracks. Most men don't.
I like my women high normal or even bit overweight.
My first wife was 5ft zero and got anorexic near end of our marriage. She was around 80 pounds at her lightest and looked terrible and that was after we/she had 3 children.
She looked much better around 100 to 110.

She definitely is anorexic like many many women.
So please keep in mind that you can likely be bit heavier than you think you should be and probably look better.

Women also need more essential bodyfat than men.

Anyway like reading your blogs. You can read more of my my posts on fasting for weight loss forum.