There are others here with way more knowledge and experience than I, but I treat it more as an 'extra calories' excuse. Like you, I'm trying to stay under 20g carbs, as I'm still fresh into the process (I lost 40 lbs about 8 years ago doing Atkins). Better to stay with your carb goal as is, until you know you've gotten past most of your 'insulin resistance'. Make sure you're getting plenty of water--that may be hard if you're a working chef in a kitchen. Most of my life I've pooh-poohed the idea of drinking lots of water for hydration's sake if you're not over-heating or indulging in intense exercise, but here we're talking about a chemical process (the burning of fat) that sounds like it benefits from the extra H2O in the system. Welcome, and we look forward to some interesting lo-carb recipes!

To a very small extent. Exercise does help to depletion glycogen stores in the muscles and liver, but to much exercise promotes cortisol.

Basically, just stay low carb and exercise intensely a couple of times per week at most.

Keto-sticks are not exactly a solid method to measure. Also, being ketonic and burning fat are not one in the same, however being ketonic is a good sigh.

Basically, in a deficit, especially while very low carb and fasting is a guarantee to be a fat burner.