The chain command block is infact set to always active. Therefore not needing power.
I might misunderstand this for the lack of detail but... ice doesn't instant mine unless you have a diamond pickaxe with Efficiency III or any other pickaxe with Efficiency V. Also, give us more details like for instance in what context does ice not instant mine?
Is this client side lag, or connection lag? If just client side it just means the console cannot handle running a server with 4 players and dedicates more resources to the other players than yourself.
Since those items are smaller than other items like blocks or sticks and not 16 pixels high they just barely clip the screen, this is not a bug.
This isn't a bug, as the campfire is not intended to cook the meat of any animal it kills. Also notice that animal meat is only cooked when the animal is on fire, however when a mob stands upon a campfire they do not set ablaze but just take damage.