About Fielding Character dice, do I have to have rolled a Character Face on a die in order to field it? The way the rules discuss Fielding characters, it's never mentioned that you had to have rolled the face of a die to field it.
if you are asking what i think you are asking then yes you can only field a character die if its showing a character face. because if its not showing a character face then its showing energy and you can not field energy (only use it or keep it in reserve until the beginning of your next turn). you can not receive the character die from your bag, and place it on the side of your choice.
you can also only field a character if you can pay the fielding cost. in most cases (pawns or lower level characters) they have no cost, but some have 1 or 2 or even three cost to field which can be paid with ANY kind of energy from your reserve pile.
About Global Abilities, does anyone know what the thematic justification was during the game's design for Global Abilities being usable by either player?
more for balance. the cards with global are sometimes "over powered" if they were by themselves. so if you add the global that anyone can use it kind of put yourself at risk thus justifying the sometimes low cost of the character.
Thematic.... eh.... Dr. Doom is a bad guy and can be bought?
If it really bothers you, there is a professor X that when active does not let your opponent use basic actions OR global abilities.