Make bosses optional

I agree with this. Possibly limit the types of planets that spawn limit how effective fuel is in the next sectors until you beat the boss and get "Ship Engine Upgrade X"? Then you can still explore freely but not without consequence.

 

Yes but all those games have a beginning middle and end. Sure you can run around the world but you're not going to progress anywhere.

 

Aha, if you can survive there.

 

You missed my point, I was paraphrasing the OP's flawed logic.

If you can't survive a boss, what makes someone think they can even survive a harsh planet?

 

Beating the bosses allow you to progress in ONE OF story lines. Not the only one — that's my point. There is no parts of a game, only strength of a hero.

 

Just build up your strength if you want to explore more. But most of explorations must be allowed from the start, not be locked by bosses.

Sectors now — it's dull. There is no logic: just new loot, new ores. What in the name of universe makes things like that? What with old sectors?

If there will be different sectors, so difference between them must be drastic.

 

Now there's still too little variety in each sector, that makes me feel we shouldn't have bosses limiting progression.
It'll hopefully get better later on when you can spend enough time messing around with the content in any sector.