You have me thinking about this, and I think we have to be cautious in taking the Weasleys' experience as a model for all wizarding families -- for at least two reasons: First, the Weasleys were and are part of the Order, so they have, perhaps, self-isolated from all but Order folks (and none of the rest of *them* have children. (Rather, the Longbottoms and Potters did, but the first are incapacitated and Neville's gran is not apparently against exposing Neville to any risks -- and the Potters are dead, but the Weasleys *do* include Harry in their circle as soon as he's allowed back into wizardom at age 11).
Second, Mr Weasley is pretty marginalised professionally and seems to be viewed by other adults either as a bit of a nutter, as a social embarrassment (downwardly mobile because of his big family and pitiful career trajectory), or as a blood traitor. So it's not much of a surprise to think that the children don't have play dates growing up because no one will let *their* kids play with those Weasleys.
We don't get a clear view of this because we see everything from Harry's point of view: in the early books he does not have a clear understanding of adult social codes; throughout, he sees the Weasleys through rose-coloured glasses (he loves this big family that embraces him); and as he gets old enough to see more clearly, the political situation gets dangerous and the Order circles the wagons so its no wonder that the Weasleys rarely socialize with other families in Harry's presence.
Last thought: One example of a big social gathering that might stand as evidence in your discussion of the dangers of letting acquaintances through your wards is the Weasley wedding in Book 7. An extreme case, but a case in point for your argument.
Re: But then Questions Arise...
First, the Weasleys were and are part of the Order, so they have, perhaps, self-isolated from all but Order folks (and none of the rest of *them* have children. (Rather, the Longbottoms and Potters did, but the first are incapacitated and Neville's gran is not apparently against exposing Neville to any risks -- and the Potters are dead, but the Weasleys *do* include Harry in their circle as soon as he's allowed back into wizardom at age 11).
Second, Mr Weasley is pretty marginalised professionally and seems to be viewed by other adults either as a bit of a nutter, as a social embarrassment (downwardly mobile because of his big family and pitiful career trajectory), or as a blood traitor. So it's not much of a surprise to think that the children don't have play dates growing up because no one will let *their* kids play with those Weasleys.
We don't get a clear view of this because we see everything from Harry's point of view: in the early books he does not have a clear understanding of adult social codes; throughout, he sees the Weasleys through rose-coloured glasses (he loves this big family that embraces him); and as he gets old enough to see more clearly, the political situation gets dangerous and the Order circles the wagons so its no wonder that the Weasleys rarely socialize with other families in Harry's presence.
Last thought:
One example of a big social gathering that might stand as evidence in your discussion of the dangers of letting acquaintances through your wards is the Weasley wedding in Book 7. An extreme case, but a case in point for your argument.