Answer
(Fatwa: 48/48/M=1432)
(1) It is not right to travel in second class to save money when you get the expenses of first class. It is against religion. And if you have to tell a lie, it is more contemptible. Yes, if you talk your owner in clear-cut words and he gives the expenses in your possession and gives you option to spend it as you wish, then it is allowed.
(2) If you turned poor and destitute after your money was stolen, you can use the interest money.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband