ive put gasoline in a 2 liter bottle before. it didnt melt... this was probably 10 years ago though so who knows? try it though. whats the worst that can happen? put a cup or two of gas into a plastic 2 litre and see what happens. it wont melt right away or... go to the gas station and buy a 2 gallon gas can.
you just need to train your body to get used to the long trips. you rode 1000 miles in 2 days, when your body is used to riding 100 miles an entire week or whatever. shit is gonna get sore. and get your wife her own bike.
helmet locks are basically worthless. if someone wants the helmet, they will just cut the strap. carry your helmet with you. chicks dig it. never leave the helmet.