Thanks for the the great info. I'm in the third category but open to walking around, it might turn out to be fun. I bought through Steam so I'll watch for a sale. I have time since the Type 8 won't come off early access until November. Probably be a Christmas sale shortly after that. I am curious to find out how a SCO designed ship flies with that feature but I can wait. The SCO I have on one of my Type 9 ships is ... interesting. This game has come so far from the Commodore 64 days it's fun that it is still around and shows what a great original concept the OG had! Playing ED is a nostalgia thing for me. Bought my first copy off the software shelf at a Sears store way back.
I feel like calling the on-foot activities "walking" is to undersell it just a little bit. Most of the travel to do Exobiology can be done in a ship or an SRV, but you need to actually get your boots on the ground in order to get those sweet, sweet genetic samples. Personally I enjoy the opportunity to get out of the vehicle and stretch my legs while enjoying the views on some distant uninhabited planet, but your mileage may vary on that.
But within inhabited space, planetary surfaces offer places where one can get up to various kinds of mischief:
1) I think the on-foot Combat Zones are fun, although if you're a skilled FPS player then they might be on the easy side.
2) There are both legal and illegal takedown missions in which you have to find an individual in a settlement and then relieve of them of the burden of existence. The mission may specify that it be done "clean" or "professional", which requires being sneaky and/or not hurting anyone else, but if not you can just kick the front door in and start blasting. I prefer the latter.
3) Shutdown/sabotage missions. Go to a settlement and mess about with their infrastructure. I think these mostly require one to be discreet, but I'm not sure since I'm more of a shooty-shooty type and haven't tried them yet.
4) Re-activation missions. Go to a shut-down settlement and re-activate its reactor. Good for collecting materials since you swipe anything that isn't nailed down, without any locals round to get annoyed at your sticky fingers. You may encounter hostile scavengers whom you can freely blast.
5) Crash site/stash retrieval. Go to a nearby planet and recover something. You may or may not be assaulted by ne'er-do-wells in the process.
6) Courier missions. Take an object to someone, or go to someone and retrieve a package from them. Basically space postman, except you may be asked to move contraband to provide some excitement. With the recent increases in material rewards for completing missions, these are now good for things besides sight-seeing and role-play.
That's what I can remember off the top of my head, there may be things I have missed out.