Do you move your sims around a lot or stay "local"

Sort of. My very first family left her home to kick off the legacy family. The game play was pretty much a rags to riches play through except my sim was in debt because they bought an empty 64x64 plot of land and they needed to pay it off before they could start building or having any kids. That 64x64 lot is meant to stay as the "legacy family" land no matter what happens in my game.

I play with death on, but lifespans set to long.

Currently my heir to this land is in college, I make it a habit to follow wherever the heir goes, and while I do try to complete some story arcs for other members of the family, everything I do must work around the heir's life. For example, the heir is going to do campus for their 2nd,3rd and 4th year of college and I am going with them, so I need to get everyone's life where I want it before we leave for college.

While at college, the only remaining family in the household passed away, and the game gave away all of animals and since no one is there to care for the land during the last year in college, I decided to have the land get caught up in courts (We don't have a job and can't afford the land right now), so now my sim needs to live elsewhere until the courts finish the inheritance paperwork and we can afford to pay the bills on that land.

So the land plays an important role in my legacy, some traits may cause them to lose the land, and then the next generation will try to get it back b.c its important, others may live someplace else until they feel they can inherit, or some may just live somewhere else until their parents die and they take over. I bounce around in the places I live to keep things fresh, but I also remodel the land for some families.

I don't know how you play or what you like, but you can move families around and boomerang back to the "main family" home like I do, or you can keep them grounded, or you can have them move for every generation, whichever you find more enjoyable to play.

I usually only play Legacy style with the Random Legacy, so it depends on what I roll. You normally have to stick to the the stating lot, but there are a few rolls that require or prompt a move (such as when solving StrangerVille's mystery). I forget sometimes though, and move Sims into worlds that make sense for their rolls.

I definitely move around. A part of playing for generations is discovering new gameplay, and I find I do that more if I move around, trying to really explore each world to the fullest before moving on. So far in my current save my sims has lived in Willow Creek (with Newcrest as a different part of town so moving freely between the two), Britechester, Glimmerbrook, Del Sol Valley, Selvadorada (very long "vacation" while exploring the joungle), Mt Komorebi, San Myshuno, Chestnut Ridge,  and Oasis Springs and Strangerville (one family in each). They've also vacationed or lived temporarily in Windenburg, Tartosa, Sulani and Tomarang. So yes, they definitely move around and will keep doing so. I'm only on gen 3 at the moment, and have plans to explore the rest of the worlds in time. 

My Sims move around when starting a new generation. I'm on the 12th generation and they've lived in many neighborhoods. I don't think I've lived in one house for 2 generations. It's not easy to move, I take so many pictures, they're all over the house. Plus, the houses are all large, since my heirs always have many children. Harley, from my 2nd generation, won the lottery and the money passes to the next heir. 

I plan on always having either an heir or sibling live in the family home. I made my founder's home in Newcrest. I do want the heir to be able to explore worlds and since I'm doing the Pack Legacy challenge, it'll be necessary at some point anyway. 

I personally don´t do the rule of staying in the lot. Why?

Doesn´t feel right to me. You would assume some sims might want to stay in the house, some other sims might rather another lifestyle like... ranch or.. country side or even city life. And I personally don´t ever choose a 64 by 64 lot when playing legacies. It is genuinely too much for a legacy.

I always find it weird but amusing when people have a horse in their legacies but they are in a 30x20 lot in the middle of coperdale.

As far as siblings I move them "out" of my sight. Meaning, lost in the outer world but nor really any specific lot or world.

I don't really have long legacies going yet but I do bit of both I think depending on size of the house and if I'm moving sims to university or something or nah

I also play multiple households in same save so I do quite a bit of population control through deaths which makes this somewhat less frequent problem to deal with as the dead have backyard to live on 😂😇

I wouldn't say I move my sims a lot, but I do move them sometimes and I love it, because sometimes moving is just the change I need to make playing my sims interesting and fresh again.

Maybe you can move the kids out and if it doesn't feel right they can move back? I've done that with my sims for example once my teen sim moved into a haunted abandoned house and lived there for some time and then I moved her back to live with her grandma.

The matriarch/patriarch usually stay in one place, but I definitely move out most of the kids, definitely the ones I plan on continuing to play. Maybe one child (the youngest?) stays at the original homestead to take over the place eventually, but I do move out other siblings so they can start new lives. Some siblings, depending on my goals, may get shipped off to apartments in San MyShuno and then changed to unplayed so I don't need to deal with them anymore, but most I usually try to play rotationally, depending on what I'm trying to achieve. That next generation may or may not stay in the same place they originally moved to. Sometimes they outgrow the place with their own kids, or sometimes I just find I don't like the lot after playing with it for a while so they move because of that. 

I try not to move my sims around too much.

 If the family size increases and I can't expand the lot that my sims are living on then I search for a new perfect home for them to settle in.

My newlyweds living in apartments always upgrade their living situations and move into a hood/house where they can plan for a family.

Most of my sims are young adults, single or about to wear the ball and chain (get married.) I love playing young adults because they make adulthood more fun when I advance to that age.