Only if you're not producing enough bile acids, in which case, you can either switch your fat source to something like coconut oil, which is about 50% Medium Chain Triglycerides (MCTs) - they digest without requiring bile by getting turned into ketones, or you can supplement with ox-bile.

It's very easy to know when it's not working, look at the Bristol stool chart. You want type 4 poops - that is long and smooth and sinking. If they float, the fat isn't being digested properly. Ditto for the other types by degree (although other factors can cause them.) You also don't want them to look pale in color.

I myself don't have a gall bladder and regularly eat a very low carb/high fat diet, mostly from coconut oil, coconut butter/milk/cream, ghee/butter, bacon, avocado, extra virgin olive oil, (as well as mixed salad greens, various meats/fish/shellfish) and while I supplement with digestive enzymes, I normally produce type 4's - so it's not that hard on the liver, even for someone without a gallbladder.

I also do a 16/8 Intermittent Fasting (IF) almost daily - except on the day after heavy work outs, meaning I skip breakfast, so there's plenty of time to allow for autophagy and healing.

I suggest reading a good paleo book if you haven't already, I recommend Primal Body, Primal Mind which is one of my favourites.

Depends entirely on the fat.

If those fats are trans-fatty acids and processed vegetable oils devoid of their natural vitamin E content, then yes.

If those fats are from fish, ruminants (preferably grass nibblers), cold pressed seed oils, coconuts, and non-rancid nuts, then no.

Poultry and pork are sort of a gray area, depending on what they were fed.

Livers also filter out environmental toxins, so even if you are eating pastured ruminants, if they live next door to a farm with a lot of pesticide overspray, or a downwind from a factory with uncontrolled emissions, you could still potentially end up with an unhappy liver on your hands.

One of the most taxing things on the liver is chronic overconsumption of concentrated fructose, so eating a box of Girl Scout cookies washed down by a Big Gulp would be a mean thing to do to your liver.

I think most people can handle the 3macronutrients well if they are not denatured. Fat, CHO or protein as long as it is unprocessed or stable in the form eaten most people can handle it. Of course, I understand that certain groups of foods cause problems in some people. There is also the genetic and epigemetic history of an individual. When I mention stable, an example would be PUFAS .....great for most in their natural form.... Not heated or hydrogenated as they are a large component of cell membranes. Plenty more to say but it,s damn hard typing on this iPad with 2kids at me for attention.