Yes.
no
You should not run gas from the furnace to any appliances.
I have gotten friends going after they have run their homes out of oil with diesel until they could get a delivery.
If you are talking about standard #2 diesel fuel oil and not motor oil and you have a #2 oil fired furnace or boiler in the home the answer is yes .
Don't try to do it yourself. Be safe and try to get a furnace technician to help reignite the oil/diesel furnace from a company that specialises in furnace repair instead.
If your furnace is opperating correctly and the vent is in good opperating condition, You can run the furnace non stop forever.
what type of "HEATING OIL" #2 #4 #6 (Bunker C )
In general, yes. But they've put big taxes on diesel. I have also converted an #2 oil furnace to reliably burn the motor oil from our van fleet
Gasoline engines cannot run on diesel. Only a diesel engine can run diesel. And a diesel engine cannot run on gasoline.
yes you can as a temporary solution but MAKE SURE you don't accidentally use gasoline or you'll be sorry
Diesel engines run on diesel fuel. Gasoline will destroy a diesel engine.