What is the likelihood that glycosuria would occur in the absence of diabetes? Will glycosuria cause kidney damage? Would a UTI cause glycosuria?

A small minority. of people will have slight glycosuria, either normally or due to a genetic kidney disorder. It doesn't generally cause damage to the kidney; elevated glucose, however, will damage the kidney and many other organs. Discuss w/your doctor. Glycosuria can increase potential for uti, not the other way around unless your blood sugar increases.
Unusual. Glycosuria is almost always caused by elevated blood glucose levels, usually due to untreated diabetes. Other causes include pregnancy, liver disease, kidney filtration problems, & benign glycosuria which occurs without significant disease. It is not common in UTI. I don't believe glucose in the urine causes kidney disease; kidneys damaged by disease (diabetes,etc) will not reabsorb sugar properly.
Renal glycosuria. Mild damage to the proximal tubule is quite common and if the blood glucose and hemoglobin A1c are okay, it's "renal glycosuria". Some lucky folks have this genetically and can eat more without getting fat. Or it can warn of Wilson's, medication allergy or some other very worrisome thing. Truth be told, a workup's in order.