Update: 6 years since my original post, all numbers have essentially doubled. Thoughts from the group?
You should be good. Like Aerides, I don't think you should count the home equity or 529 as assets to be used towards retirement.
Have you run stuff through firecalc? I retired with 2 kids in middle school. But we had the 529s funded and we never expanded our lifestyle. Now they're in college and life is good. It was a great opportunity to be available and 'in their business' during the high school years. Able to vet their friends and have the time and bandwidth to drive them to sporting activities.