Is there a way to remove the little X crafting Y inventory hints ?

yeah. in your settings. you can turn youre hand off, the hub off, tips and tricks, etc...

The Y button only drops it from my inventory. But you were close, it's the left thumbstick, press that in and it either removes the red X or gives it a star for favorite.

Nice world, but this is the PC version of the game, not the Xbox version. In the Xbox version, it says to push X for crafting and Y for inventory in the bottom left (there are now hundreds of videos on YouTube of the Xbox version and every single one has
that in the bottom left). That appears nowhere in the video you link to, so this is quite obviously the PC version. Why are you trying to pass off something created using creative mode on the PC version as having been done on the Xbox?

One of the button instantly sells all the junk in your inventory and keeps the crafting items.

This is a known bug in Minecraft, i had the game freeze for me when opening my crafting menu, the way i solved it was join a friends game. Sleep in a bed, have it save the game. then rejoin the game, or you can try making a game, saving the game before opening
the inventory, exit the game, load your game back, and see if it will let you navigate through your inventory.