Wrong - jet fuel is the best fuel but it can use any fuel. Parts delivered from US German and other stock piles in 3-4 hours.
UA is installing portable 100 ton bridges every where.
M1A1’s weight is probably not “too high” for primary roads & bridges in Ukraine, and really not hugely higher than the Leopards (depending a bit on which Leopard variant.) M1A2’s weight otoh IS problematic, but SFAIK no one is talking about sending A2’s. Still, the best bet might be to use the M1’s primarily as a deterrent against Russia attacking Kyiv, with the now “freed up” Leopards out in the fields, so to speak, in the east and south. That helps with maintenance and fuel consumption. Ukraine’s air defenses are probably good enough at this point to keep Russian aircraft at bay (current situation) unless Pooty decides considerable aircraft losses are acceptable. Long range missiles are not much good vs. tanks, but drones can be a problem (for both sides).