Yes, you can use reverse holo cards in tournaments without any restrictions
This is Shock with upside, and the upside is real -- since in the late game it can deal with much larger creatures or finish the opponent off
Clara is specifically designed to work with every Doctor, doubling up their triggered abilities to give you all sorts of value from your decks
Plague Wind was part of a cycle of Wind cards that had prohibitively high mana requirements (all were nine mana) but boasted game-breaking - at the time - effects that altered the fabric of the game
The tools with which most stax lists operate disruptive countermagic, Rule of Law effects, etc., are also those tools which lead to long games, something which not all stax lists are necessarily primed for in perpetuity
Honestly, youll be happy with either