How does Q7A deal with the addition of seed crystals to induce crystallization with respect to: amount of seed needed and used, type, i.e. particle size distribution of seed material, and documentation.

This is a very specific situation that Q7A does not address. However, Q7A says you have to
describe and document your process. Seed crystals would fall under the definition of material,
which is a general term to denote raw materials, process aids, or intermediates. If the seed
crystals are critical to the API quality, then it should be considered a critical process and
controlled appropriately.