This is completely incorrect. Less than 25% of the amino acids that reach the liver even make it into the bloodstream (with most of what's released being BCAAs). For example, consider
research like this where amino acids were not just ingested, but infused into the bloodstream. What happens to them? 70-75% are absorbed and used by the splanchnic bed (liver and gut) while only 25-30% are absorbed and utilized by skeletal muscle. Most of what's used by muscle are the BCAAs. However, the liver uses amino acids for all sorts of other things, including oxdiation and gluconeogenesis. It's not "only maintenance of protein based tissue that requires amino acids." Protein-based tissue is not even the primary destination for amino acids.
Wrong. One of the major reasons obese people suffer from fasting hyperglycemia is because glucogneogenesis is accelerated, even in the face of an excess of fatty acids. Going by your logic, they don't need to take any more protein, since they have the same amount of muscle. Unfortunately, that's not the case. These obese people have greater protein intake requirements, one reason being that more is lost through gluconeogenesis. There's also the fact that they DON'T have the same amount of muscle. They actually gain a lot of muscle along with the fat, which is another point you've been ignorant of.