Wow.... I think Bucks County is a great place!!! I've never seen such negative stuff posted about it. To each her own course! :)
I don't know of anyone renting but you'd probably want to look at the New Hope/Solebury area, Doylestown, Warrington, etc. You want to be near route 202 which is a straight ride to Raritan. As far as the roads go, I guess it depends on what you are used to. Once you go north of the New Hope area, Bucks County gets very rural which i LOVE! But I can see how others would view it as a negative with long winding roads.
If you stick to the New Hope area (or close to Rt 202, I think you'll be fairly equidistant to Spring House and Raritan - it's a matter of going in opposite directions on Rt 202. Rt 202 is a 4 lane road for much of the trip (not exactly a highway b/c it has lights and stuff and it is 2 lanes in a couple areas). Part will be smooth sailing and part will have heavier volumes of traffic. I'm not sure about spring house but there is traffic around Raritan. I commuted that for years and I didn't find it unbearable - just annoying.
So, area stuff.... New Hope is a quaint somewhat alternative town. The downtown is narrow but walkable. I'm betting you and your kids would love the Howell Living History Farm right across the river in NJ. It is a farm that is run the way farms were run around 1910. You can google it for the website. I haven't been there in a while but there is Whole Earth in Princeton for the basics (bulk flour, etc). There is a knitting store (I think it's call The Wooly Lamb) in Pennington NJ which my friend's mother loves.
The housing is not cheap but i don't think the taxes are terrible there but I live in NJ now where taxes are completely insane. However, taxes in the Allentown /Easton area are much cheaper so I can see how the area looks expensive. Schools are wonderful if you do ever use public. There is a wonderful coop in Pennington NJ - Honeybrook Farm - where you can join and pick your own food. There are plenty of more commercial pick your own farms. Real milk can legally be sold in PA. I'm sure once you get to the Waldorf school, families can point out the best places for local food, etc that you want. I just don't live close enough to think of any places!!! There is also a Whole Foods and Trader Joes in nearby Princeton. Good luck!