Answer to number four:
Lifting the vehicle or not lifting the vehicle will not change the behavior of the pump. The pump pressure gauge reads the difference between the outside air pressure and the "inside" air pressure. If you observe a tire while being inflated without problems from the compressor, you'll see that the footprint of the tire, the portion of rubber in contact with the ground, will decrease as the tire pressure increases.
If a tire is loaded to exactly five hundred pounds including the weight of the tire and wheel and filled with air to fifty pounds per square inch, the rubber in contact with the ground will have an area of one hundred square inches. Allowances must be made for inaccuracies in the measuring devices and for sidewall stiffness of the rubber and other factors, I'm sure, but the ballpark figures are good enough.
There are Department of Transportation inspectors who use nearly flat "scales" which are really high resolution pressure sensitive panels. The driver is instructed to place a tire on the panel, the area of the panel is measured and the weight is determined without moving parts.
If you lift your vehicle to inflate the tire, it means there is no footprint of rubber on the ground, but no other considerations are involved.
Answer to number five:
The volume you can produce with a bicycle floor pump is miniscule compared to that required to fill a vehicle tire. Many moons ago I received a floor pump for a gift, along with a five gallon air pressure storage tank. My friend and I thought it would be fun to pressurize the tank using the floor pump.
The friction of continuous operation of the floor pump softened the plastic chamber of the pump. On one of the fill strokes of the pump, the lowered internal pressure pulled the softened plastic into the cylinder, making an hourglass shape. Very short lived gift.
You would wear yourself out, or wear the pump to the point of uselessness attempting to fill a vehicle tire of such volume. I've done it. (wear myself out!)
Our vehicles were not sold with spare tires. They both have inflator pumps and a can of fix-a-flat. Knowing that we could be faced with the same circumstances you experienced, I purchased a large quantity of CO2 cartridges and a schrader valve inflator to fit. It's likely I would use a few dozen of the cartridges if I had to attempt an inflation, but it beats the alternatives.