Hi K., Welcome to Minneapolis! I hope you enjoy your time here. I grew up in rural MN and moved to Mpls/St. Paul after college 28 years ago. I've visited many other places, but love it here! The Lakes area is beautiful, and the suburban areas are also nice places to raise a family.
I live in Minneapolis, close to Lake Calhoun actually, but lived in the suburb of Eagan for almost 20 years prior. Eagan is similar to Lakeville, etc. My ex still lives in the Eagan house. I have a 9 year-old daughter who shares time between me in Mpls and her dad in Eagan.
We don't have a fenced yard in Eagan, and none of our neighbors did, either. When we moved in, in fact, our new neighbors warned us, fairly seriously, that we would be shunned if we built a fence. The neighborhood borders on a wooded park and a fence would block the view.
We don't always keep our kid in our yard and other kids out. Sometimes, all the kids in the neighborhood play in a "pack" that roams between back yards and I love that about the neighborhood. All the parents are involved and watchful and the kids have a chance to have a bit of freedom. There are times, of course, that you tell your kid(s) to stay within view. If they are too young to listen, you go out and play with them. This is an opportunity to chat with the neighbors, too.
My ex now has a German Shepherd dog. He has the dog on a tether, if he's not right there, otherwise, he's trained the dog to only run in their own yard, when she's let out for short breaks or he's on the deck and watching.
Your realtor should be able to answer your questions about the pond. If it's purely a drainage pond, there is no maintenance that comes with that.
You seem very concerned about liability. I'm sure you will have regular liability insurance, and that is for accidents that happen to people on your property. We've lived there for 18 years, have a playset, and haven't had an accident.
Water drainage and possible flooding are something to look at closely. We ended up spending a bit of money putting in in-ground drainage tile, better gutters on the house, and replacing flooring in our basement. The house does not now have any water problems. A home inspection should find those issues, but I'd look closely at basement walls and flooring for any signs of water, or recent new coverings...
The main bug complaint here is the mosquitos in the summer, but they aren't too much of a problem in residential areas. If you decide to go camping, you'll experience MN mosquitos! Most other bugs are kept under control by our cold winters (yay!)
I don't know what type of commute your husband is used to, but from Lakeville to Mpls will be about a 40 minute drive during non-rush hour traffic, up to 60 minutes if rush hour, or snow/rain. The area around Lake Calhoun is extremely popular in the summer, so that could tie up traffic, too. There is a "diamond lane" on 35W now that I would pay the fee for if I was regularly commuting. That would save some time and frustration.
OR, I would take the bus from Lakeville, bring my bike (the buses have bike racks) and bike from the closest spot on the 35W route to Lake Calhoun. (But then, I enjoy being a non-traditional commuter, and the bike trails in Mpls are awesome!) OR, transfer buses from 35W to his office. (http://metrotransit.org/)
I don't know much specifically about those school districts. All the south suburban school districts are good, generally, with relatively new school buildings and fewer budget or political problems that the city schools. Sadly, all schools are having some budget pressure. We've been extremely pleased with the schools in Eagan.
Let me know if you have any more questions!
S.
Added: I like Cindy L's suggestion of considering Edina, St. Louis Park, or Eden Prairie. All have excellent schools, more likelihood of fenced yards, and an easier commute to the Lakes area (whether by car, bus, or bike).