There's so much variation in PETG filament between brands that I would do a temp tower, just to be sure. I've had "PETG" that worked best @ 235C and 260C.
Play with retraction. It looks like that printer has a Bowden setup, so the range of length can vary a bit, but I've had success turning retraction off, as well as setting it to 6.5mm. It kinda depends on the geometry and filament heat retention.
I try to avoid getting near the printed part during travel - there's always some little hair that catches the nozzle as it flies by.
And like others said, coat it with something to fill in the tiny pores. I generally have some thin epoxy lying around for stuff like table tops. You can basically use anything as a colorant in it. It very slightly yellows with UV exposure, but the worst I've seen the decent stuff get is similar to a very slightly warm white from an incandescent bulb. A tiny touch of blue should make it weather nicely.