Most houses in that range are going to be on the quieter side of things. Traffic in Columbia tends to flow to major roads, so aside from the downtown or merryweather district, the traffic inside neighborhoods isn't too bad.

"Good" schools is going to be really subjective. Some of the highest ranked ones have minimal diversity. And, while there will be lots of opportunities for your kids, there will also be a lot competition for them and within them. Some parents prefer smaller schools for that reason. Either way, a good gauge is to look at the percentage of parents in the PTA.

As far as neighborhoods being good for kids - again this is going to be your preference and how you raise your kids. Columbia Assessed (part of the Columbia Association) properties tend to be on a network of wonderful biking/walking trails with tot-lots for kids. The houses will be older (60s-70s) and the lots smaller, plus you get an extra tax. I think it's all worth it, since this can build a sense of community within in your neighborhood. Conversely - some people prefer to move into the new-builds. Houses and yards are bigger, no CA fee, and if you can find one of the newer neighborhoods there will be more kids.

And, after doing all the research, know that school zoning does and will change.