Wife Swap is an enjoyable romp that is leagues above Trading Spouses. Primarily, I see the show as follows:
Positive Messages: The only message here is about how the grass may or may not be greener on the other side
Positive Role Models: Some wholesome families have appeared on occasion, but mainly the families live their own crazy lifestyles. Some act like pirates and clowns, others push their kids too hard, and others simply are lazy and stubborn. Typically, the dads/husbands are the worst members. Despite this, there's lots of things that positively affect them.
Violence: Not too extreme, but property destruction and occasional violence during roundtable meetings have ensued.
Sexual content:Some talk about virginity and dating has taken place
Language: It depends. Most of it is sensored, but some is not. The a word is about as bad as it gets.
Consumerism: Some families have shopping addictions, but no actual product names are shown
Alcohol: Not much of an issue, though some episodes show the wives drinking at a bar.
Overall, this show may not be a good fit for your youngest, but anyone over the age of 8 can handle it