Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
Venusaur learns Earth Power, no need to resort to the physical move.
252+ SpA Life Orb Venusaur Earth Power vs. 252 HP / 252+ SpD Coalossal: 364-432 (85.8 - 101.8%) -- 12.5% chance to OHKO
Setting the timer to automatically start in the new battle options leads to getting a message like this every time I watch a battle.
BUG STATUS: FIXED by Annika
The link in the OP explains it. Basically for this month only stuff with super-low OU usage got to drop multiple tiers at once to speed up the process of getting things to the right place.
I was trying to figure out if a (physical) Water move would 2HKO Palossand through Water Compaction and I think it would be really nice if there was an equivalent to the Draco Meteor "twice" button for this. Also relevant for Stamina and Weak Armor.
Thanks for all the work on the calculator!
Rising Voltage specifically doubles in power when the target is on terrain i.e. grounded. So running it over Thunderbolt does mean that for instance Specs Koko wouldn't be able to OHKO specially defensive Corviknight. (Presumably still worth it, but there is at least a small drawback.)
Why is Sludge Bomb preferred over Sludge Wave on Toxtricity? I'd have assumed that the greater power was more important than the poison chance on an offensively oriented mon.