There's not an easy answer to all these questions as some of them are subjective in terms of value and # of editions, artists try different things and see what works!
On nftshowroom the collection name is displayed beside the art and title so if you do different series you can add them to different collections. If you don't want to do that you can just make one collection eg. Patchsworks art and tokenize everything under that one.
We have a max upload of 100mb for Mp4s so the max length will be limited by the ability to compress under that size. I have successfully tokenized a 3 minute music video but more than that would be near impossible lol. You can use the unlockable function to add extra content if you like.
I have made a collection of posts here that have some info on marketing, etiquette suggestions etc that you may find useful. It is pinned in the nftshowroom blog!
https://peakd.com/ccc/nftshowroom/nft-showroom-artist-resource-collection
Thank you so much. The collection of helpful posts is awesome! Meet you soon on nft showroom...