Difference between Sectors?

[Char;y]

What the major differences between sectors, apart from the obvious difference in ships?

Do some sectors contain more shops? I once found four in a civilian sector. I tend to avoid nebula sectors, as they seem to have less shops.

[xdiesp]

Methinks the rebel fleet flies a little slower in nebula sectors overall, and sensors are off, plus the different possible events. But the biggest difference comes from the ships you might encounter, at progressively higher difficulty.

[Agent_L]

What the major differences between sectors, apart from the obvious difference in ships?

Every beacon has one "event" tied to it. The even may be a shop, a quest, an enemy ship, nothing - you get the idea. Now, every type of sector has different list from which events are randomly chosen

Do some sectors contain more shops? I once found four in a civilian sector. I tend to avoid nebula sectors, as they seem to have less shops.

I'm now looking into data.dat, It seem you're right: "Uncharted Nebula" should have 1 or 2 stores, however "Slug Home Nebula" and "Slug Controlled Nebula" should have 2 to 3 shops, just like "Engi Controlled Sector". Mantis sectors also have 1-2 shops, so it seems number of shops is more related to how hostile the sector is, not is it clear or nebula.