Josh,
Actually, you're off to a good start and you have exactly what I envisioned and explained. The user would create the Category child records in the Grid Edit report you have there. The Estimate parent record would be created at the same time as those child records.
If you ever wanted to make edits, just pull up the parent Estimate record, or, you can open each individual Category child record and edit those individually in their own form.
But, what you have here is excellent, and you're demonstrating an equally excellent understanding of QuickBase and how it works.
