The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
I don't know that there are any tropes for what you're asking specifically, but some comments and observations:
1. Games like The Old Republic lean on things like Planetville and City of Adventure where the entire planet is represented by a few square kilometers and everything worthwhile is within arm's reach. No one really wants a quest giver who says "A hundred miles from here, I lost my quart of milk, can you go fetch it back for me?".
Sometimes the "everything's right next to the quest giver" style is referred to as Theme Park MMO. Each quest giver points you toward the nearby "ride", you ride it, exit, and collect your reward. Repeat to infinity.
2. The planet order is Sorting Algorithm of Evil where Planet 1 is easier than Planet 2 is easier than Planet 3, and so on. And there may be multiple "Planet 1s", but everyone still starts on one of them.
3. That they happen to recycle the same areas just strikes me as Anthropic Principle — they do because that's the story being told. You're not playing as just random freelancers who happen to share footprints, you're playing as people with specific histories who are pulled into a specific story, and these planets are all major hubs for activity.

Is there a name for a trope where all of your objectives in a game just so happen to be in the same area? World of Warcraft and other MM Os specifically come to mind, where you'll get a bunch of quests from different characters, and yet everything you want to accomplish all happens to be bunched together in a small area. Bonus points for Star Wars: The Old Republic, where all of the different class storylines also happen to hit up the same areas in the same order, despite their totally unconnected plots.