It maybe lots of things. Check the free, easy ones first. Check the battery cables, are the loss, frayed, corroded. Check the battery. Does it crank, start if it's jumped.
I have never had tire damage from chains, tractor or truck, but even on a truck it's for slow speed use in my case. They do need to be properly fitting and kept snug. On pavement, spin a tire on ice and you will scare the road or driveway.
As has been said in previous posts. Kubota and many/most manufacturers advise against front chains. If you look at the size difference between front and rear axles, it's easy to see why.
That said, I have always run all four. In many situations it's essential for stearing and control. Make your...
That close in price, unless you need the smaller footprint, I'd go for wider stance, more hp, and higher loader capacity. Both I'm sure are good machines.
Back when radiators where made of copper and brass repair shops where fairly common. I still have one about a half hour away. He now caters to older equipment. I'm sure any shop like that could repair, rebuild or make a new one. I don't know if it would be less expensive?
I don't have the 3pt specs on a b4200, but it can't be much. 220 lts. is 58 gallons, 558 pounds, 208 kg. Check yours specs. If the 3pt. can handle that much weight plus whatever mount you make, go for it. If not get a smaller container.