My 110 volt welder requires a 20 amp circuit. I reason the welder can then draw up to 2200 continuous watts. Manufacturer recommends a time delay fuse or circuit breaker for surges. Is my reasoning correct that a 120 volt generator outlet rated at 20 amps will appropriately power my welder? Does it matter what the surge rating is on the generator? Will gfci outlets be important? Is ul listing important? Any other advice? Thank you for your time and expertise.

Kinney,
Let's start with the equipment ratings... what do the welder's installation instructions call for? What voltage, phase and overcurrent protection?
You mention a generator... what kind? Diesel, natural gas, electric? What is the kilowatt rating of the generator?
GFCI is important when required by the code...
If you are buying equipment, normally all equipment sold in the USA will come with UL approval... why do you ask?
Typically generators are over-sized compared to the load they supply when the load has a large inrush... does the welder indicate how large that inrush will be?
What kind of welder is this?