Ravencoin NFT Creation Questions

There are some things about NFT creation that are a little fuzzy for me.

1. Can I create a root asset without actually making an NFT yet? Just like I'd register a domain and build the website later when I had time?

2. What is a sub-asset for? Is releasing a new NFT based on the root asset considered a sub-asset (100 RVN cost), or a unique token (5 RVN cost).

3. If you're releasing things under a single name, you only need to create a root asset once, right? The only reason you'd create more than one is if you have, for example, different "pen names" where you'd release work (like say BOBJONESMUSIC and BOBJONESART), right?

4. Say I have a series of 20 drawings that I want to NFT. Would the total cost be 600 RVN (500 for the root asset, plus 5 each x 20 for each unique asset)? And each additional drawing I'd want to add to the series later on would be just 5 RVN to create?

5. Ravencoin NFTs are not tied to any specific place and can be listed anywhere you want as long as the site supports RVN, right? And you could list them for sale on your own website, but buyers would be less likely to buy direct from some random nobody because there's not a great guarantee that you'd send the asset, right? As I understand it, just like, say etsy, asset exchanges add trust + traffic + curation layers that make the whole finding, buying, and selling experience easier.

6. Do any files associated with the NFT need to be hosted somewhere permanently? I assume that's what IPFS is for and that the files aren't stored within the blocks on the blockchain because that would get out of hand quickly, but is IPFS both required and permanent as part of the process?

Any clarification on math, terminology, and concepts is appreciated. 🙂