With pleasure!
This is an article that is an interesting read, but makes it out to be more complicated than I like!
https://www.theguardian.com/lifeandstyle/wordofmouth/2010/apr/15/how-to-make-perfect-crackling
whereas this is the simple version that I use
http://www.taste.com.au/recipes/crispy-pork-crackling/36722338-3c8a-48af-b6a4-b15e8a10cacc
You can use belly pork or pork shoulder, or buy the rind direct from your butcher, as you are doing.
and then if you want to add any spices, just go for it.
I have some BBQ and jerk spices in my spice rack (powder) which I scatter onto the pork.
But I also have a lovely smoked chipotle paste that works well.
https://www.tesco.com/groceries/en-GB/products/273912655
If you are spicing it then you may need to watch that the spices don't burn. So maybe paint them onto the pork rind half way through the cooking rather than at the beginning.
Ah, just remembered! The last time I did crackling, it was by another method, which also worked well.
I had slow cooked a shoulder of pork joint to shred for pulled pork, and left the skin on the joint in the slow cooker.
Once it was done I just peeled the skin and fat off the meat (much easier after cooking rather than having to cut it off before cooking) and shredded the meat.
The skin had absorbed the pulled pork spices while cooking and was light brown in colour.
I just laid it flat on a rack in the oven and cooked it using the simple version above. Lovely. The spice flavours had completely spread through the whole thing, and made the perfect combination with the pulled meat. Will do that again.
Re the soup. Yes, it would freeze very well I think. But we ended up eating it all before it got to the freezer! lol