On the 4x4 ones, only one tire will spin on each axle, so only two tires spin when they get stuck. I have no idea if both drive wheels will spin on the 2wd like yours (I doubt it- likely as soon as one spins, you will be done). They don't have much for suspension/ articulation on the axle for traction, so they tend to be pretty helpless. Yours only being 2wd means its twice as helpless.
I can't see chains hurting it. They are individual drive motors. Personally, if I needed chains because it was slick (snow/ice), and it was a slope, I wouldn't be much for driving it around. That's a recipe for disaster. I'd leave it in the shed until better weather.
Handy looking attachment on the excavator.
Sure is, they drug the genie out of the creek today, and I think it has something broke in it now, they had to drag it all the way out and up the bank, and then it wouldn't climb a slight grade to the parking area. The excavator basket goes anywhere.