SR2 is one of the best games, I ever played. (And I play many games) I never tried to play it on easy though. Played through it 3 times on hard and I have just started my first attempt on impossible.
In detail.
The game gets more difficult after a while. But you get the right tools to deal with it: Wingmen, better weapons and hulls, better trading routes, higher pay for missions. If you run low on money after heavy fighting, you have to go trading or doing missions again. -- Fighting is not cost-efficent, it is expensive. But you have a galaxy to save, and you can keep the honour
(some of the bosses can be eliminated without firing a single shot btw. How hard is that?)
The text adventures require some thinking. If you hate text adventures or puzzles, simply don't do the missions. You get an autosave at the start of the mission. They take some time to solve. And some of them are really hard.
The planetary battles get harder as the game progresses. It is RTS after all. Doing a lot of things in a small amount of time helps. Building the right stuff in the right oder and designing good robots certainly helps too!
About enemies getting stronger. There is different phases in the game. As technology level progresses, enemies and NPC ships get stronger. The hardes part is the start though.
Overall it is a great game. The different starting positions are for role play purposes. You start with a different background. Playing according to this background (or at least trying to do!) is part of the fun!