I'm having difficulties understanding how I can create a product to sell where the buyer can edit a text field on their own privately bought node.
I've come up with a scenario but I don't know how to construct everything.

I'm having difficulties understanding how I can create a product to sell where the buyer can edit a text field on their own privately bought node. I've come up with a scenario but I don't know how to construct everything.

Here's the scenario:
1. I create a product type A.
2. I create a product of type A.
3. I create a product display for that product.
4. I sell that same product 100 times to different buyers.
5. Each buyer has their own purchased product and can change a particular text field B.
6. I (or any store collaborator) would be notified that this text field B has indeed been changed and I would have access to see that text field B.
7. I would update a related text field C (a bit like a remark but not a Drupal comment) only on the buyers purchased node for the buyer to see.
8. The buyer is notified of the update and can view the related text field C.
9. If a buyer doesn't update his specific text field B on their node within one month time, the ability to edit that particular text field B expires.

I hope it is clear. If not, please fire your questions.

I'm not asking to create a screencast for me (of course that would be awesome) but I would like to get my architecture in order first before I actually start building only to see that I'm using the wrong approach. So if you have any idea how this would be possible, please share.

Cheerzz!