I have two step-children who fled their abusive father to come and live with me. Both of them were home-schooled for a time (about 12 months each). We learned a lot of powerful lessons from the first one, but even then, we faced huge challenges with the second one.
Some significant points:
1. Mum and/or Dad are not teachers. We're not qualified to be, and re-assurances from the homeschooling organisation are vacuous. Don't kid yourself about this. Being a teacher is a career choice, and there are very specific skillsets involved.
2. Mum and/or Dad don't want a teacher-student relationship with their child. You can't just throw a switch at 3pm and turn back into a parent. The child is not old/mature enough to process that changeover.
3. The child will lose out on a huge amount of 'non-curriculum learning'. Things like 'how to avoid the schoolyard bully', 'how to read a schedule and navigate to classrooms', 'how to meet project deadlines without parental intervention', 'how to negotiate the fickle friendships that happen in life', 'observe adult role models outside the family'. There are dozens of things like this.
4. There is research to support the position that children perform better when parents are 'hands off'. I can't remember the link, but one interesting one was posted to /. in the last 6 months.
5. Some children need real parental nurturing to get over a major life crisis. Most children do not. If your child needs that kind of care, be very careful of breaking your relationship with them by spending 6 hours every day with them.
In both cases, after 12 months, the children returned to regular schooling to a) escape mum and/or dad; and b) get a life/friends. The second one needed a little more encouragement than the first.
Good luck with it! Its been a hard road, and its only two-three years after they returned to regular school that their behaviours are starting to normalise.