The tap effect is certainly useful but in most cases it is about the most minor tempo swing on a card
Even 1 damage dealt to a creature from a source with deathtouch is considered lethal damage, so any amount greater than that will cause excess damage to be dealt, even if the total amount of damage isn't greater than the creature's toughness
Obscuring Haze: S The best fog in the game because its free, asymmetrical, and prevents all damage
Dead Weight is looking better and better, and helps race us towards delirium
Since both Feather and Dark-Dwellers have replacement effects on where that spell goes when it resolves, you get to choose which order these effects are applied
Its easy for a niche card to be strong within its niche - and sometimes a card like that is simply so strong that it takes a deck from being a fun idea into a crushing way to play Commander - but its far rarer for a card to work in decks that its not intended for