How switch download works questions?

[EleanorWyatt]

So i'm new to this kind of thing and when i tried to download a few games to get ready for my switch, but im faced with so many options that i'm kind of lost. So i put up a few questions:
1- I heard that the XCI format is the correct one to use the games, but i saw some and even downloaded pokken DX as an istorage file. How will that work on my switch?

2- I saw several links to GoogleDrive and when i enter them there are several files with coded names, should i download them all or just the latest one?

3- How the DLC and updates for games work? For instance i downloaded blazblue cross tag battle, but will it come will all available dlc? And later if more dlc comes how will i update it? Also for games with updates, should i just download them normally or what?

4- I have two digital games i bought before buying the SXPRO(xenoblade 2 with season pass and DK tropical freeze), i can leave them in my SD card with the downloaded games from here?

[Cronos]

hi , istorage is only for emulators
dlc and update they installed like a game (nsp/xci file)