LH works fine as no one is really flying more than 5000 NM. Transatlantic routes are still dominated by frequency; so my L1011s, YYZ to LHR, have been bettered by airlines flying B757s, but there is still money to be made.
As to fuel contracts: with fuel so reasonable and 9 aircraft you aren't likely going to profit from one yet. But fuel will likely spike as Rushmore notes (though strangely it didn't spike very high in the last challenge...) so getting a long term contract when you have, say, 20 aircraft, might be a good investment. Still, do the math to find out where you are: take half your monthly fuel costs and multiple it by the % discount on offer. If that amount is higher than the monthly contract cost then go for it. If not, then you need to guestimate when in the future the discount will be worth it.