All have been played against me.
It untaps your lands to let you have explosive turns, or to combo
Effects that switch the creature's power and toughness are always applied after any other power or toughness changing effects, including these two, regardless of the order in which they are created
There are lots of MTG commanders that let you cheat equip costs (in fact Captain America, First Avenger does this too), and the go-to equipment here are things like Colossus Hammer
One of the most popular formats to play is Commander, where you go up against up to three other players using a 100-card deck that's focused around one card as your commander
Cogsworth's ability can also come in handy, as it puts Hiram out of range of Maui