Yes large amounts are bad. It signifies that your kidneys are not functioning well.
Yes, high protein in urine means that one has kidney disease or their kidneys are not working properly.
A negative test result means there is no increased amount of protein in the urine at the time of testing.
No, foamy urine is not caused by eating too much fat.
Protein in urine would cause foam because protein reacts with air to form foam when you pass excess protein in urine.