I fully bled my rear brakes and didnt use half the bottle so would suggest that 1 bottle should be enough for front & back.

HOWEVER - Better value would be to go for the litre bottle and try source a short length of pipe from local hardware store or aquarium!

This bottle is enough to replace the fluid in 2 brakes, so no problem.

I only had to bleed the system so I only used a minimum amount of oil. I also refed the spillage (collected in the plastic bag) back intom the system. You can buy a larger volume of oil at a very reasonable price so it might be better to go for that purchase.

1 bottle ; Yes - if you are careful & an efficient brake bleeder.

Yes, one bottle in enough for both brakes...

You might get away with it - it depends on the hose length and if you are very neat with (ie don't spill a drop), but I would think that two bottles would be required.

If you're careful with the oil and re-use any oil that is bled from the system, a single bottle should be more than adequate, assuming the pipes [brake lines] are already filled with oil. If the pipes are empty, then a single bottle may not be enough.