Ripme,
As response to your questions, which you don't wish to explain, I offer the following.
"Question is - why bother?"
A. Because we seek either an improved quality of life or a longer life or both.
"I guess that's a metastasis? "
A. Nobody knows. It may be a primary cancer, or may be a non-cancerous tumor. To find out you need a diagnosis.
"If the tumor has been attached there for a year (or more) it must have already spread & surgery is pointless, right?"
A. Even if it is a a cancerous tumor - of whatever variety you don't wish to discuss - there is no basis for assuming it MUST HAVE "spread at one year. Surgery decisions need to be based on facts which are not present.
"Stage 4 is stage 4, the damage has already been done?"
A. Again we have that pesky point of no diagnosis. Stage is an unknown.
"so why submit myself to an unnecessary surgery?"
A. Surgery is performed to achieve a specific benefit. No expected specific benefit has been presented,
"Or would removing this tumor increase what time I have left?"
A. THAT is the question for you to discuss with your doctor(s). Life extension is one of the primary reasons people seek medical care. After a full work up and diagnosis you will be learn what is medically possible and be able to make informed decisions about your care and future.
You are free to, "think the cancer has spread like a shotgun blast," if you wish. Or you can proceed to receive a proper diagnosis and learn if you you are correct or not. You can make your care decisions based on your thoughts or a medical diagnosis. Your future is yours to choose.
Best,
Jack