Yes.
Yes. As far as in the US 220v and 240v is pretty much the same thing. People call it 220 but realistically you prob have 230-240v. Get a cheap voltage tester and check it out
Yes.
no
The device requires a NEMA 14-50 outlet, which is a 240-volt, 50-amp outlet commonly used for high-powered appliances like electric stoves or RVs.
Assuming the wiring to the outlet has 2 loads and one neutral, isolate one load from the outlet and use the neutral as the common. be sure to ground from the receptacle to your conduit or ground lead. You should also replace the corresponding breaker with a 120 volt single breaker.
Yes
The bulb will be about half as bright.
Yes
A device that operates on a 220 volt 20 amp plug requires a special type of electrical outlet called a NEMA 6-20 outlet.
A device that operates on a 240 volt 50 amp plug requires a NEMA 6-50 electrical outlet.
yes
If I understand your question, Can you run a 110 appliance off of a 220 volt outlet? You could by only using one leg of the 220. You may also consider changing the outlet. Put in a regular 110 outlet and capping off one leg of the 220 in the wall box. You still have a neutral and a ground to work with. I read this as the questioner doesn't want to modify the outlet. Check the voltage ratings on the device. Many electronic devices nowadays can havdle 120V or 240V as it is cheaper to manufacture one powersupply and sell it everywhere. If your device is rated for 240V, you can put a 240V plug on it. If it only says 120V, no dice. 240V will burn it up.