I don't know about other difficulties as i directly went with "hard" mode.
Xp is really slow to get, but it's the pleasure of challenge i like.
Some missions were a pain in the ass at the very beginning.
About the money i already got a lot of money in some missions like 200.000 and more recently 750.000, but perhraps you got more in easy mode i don't know ?
Anyway Salvaging is a great way to earn money, i scout systems sometimes
after conflicts between 2 factions and i happen to find a lot of things i am reselling, as for the escape pods turning them into money and XP.
All i know is with what i get in "hard" mode with the challenges i had to overcome, i feel pretty good about the rewards in "hard" mode. I even feel powerful some times even if i am still in 3rd generation fighters
