(Sorry, it's another Autotap request. There appears to be a similar one in nature, re: Talismans killing the caster instead of Autotop using other mana sources. :)

1 -- Cast Channel. Cast Kozilek's Command down to 1 life choosing Eldrazi Spawns as one of the mode. Cast any (colorless) spell with cost >= life total.

2 -- Mac (but it's probably on all clients)

3 -- Autotap prioritizes the Channel mana -- killing you on cast! -- instead of using other sources like the Eldrazi spawns. (I suspect Channel mana might also be prioritized over e.g. mana-rock mana, but I haven't validated).

[alternatively] It is very hard / slow to "manually" pay costs with Eldrazi spawns. I routinely time out trying to click them one by one. (The animation for a spawn disappearing takes a significant time, during which time all clicks on other spawns are ignored.)

4 -- Autotap never prioritizes killing the caster.

[alternatively] Make it faster to pay for mana with Eldrazi spawns. Allow repeated clicks/taps on spawns during the animation of a previous spawn.

5 -- N/A

6 -- Manually clicking my other mana sources (Eldrazi spawns) very slowly.