Okay, in order.
- Yes, for Casual plays no problem. The issue is summoning them tends to be far too complicated due to the specific tuners they require and how their effects activate on the battlefield leaving them open to other effects, which means your opponent can get rid of them before they get the chance to do anything.
- There’s call of the haunted, soul charge, graceful revival for your tuners and damage gate to get the materials directly from the deck
- Links have arrows that point to different parts of the field. The new master rules made it so that now there’s only 1 extra monster zone for each side, and in order to make more extra monster zones available, you need link monsters that point into a monster zone (the normal 5).
It’s vital for extra deck dependant decks because you need to have more than one on the field at a time, in this case the sun and moon dragon.