What do they grey numbers mean?
The grey numbers indicate resources of any color. For example "2" in grey means that two resources of any color must be attached. This flexibility is provided on most cards so that they can be rearranged into custom decks once the base game is mastered.
When a card says "voids all invocations", does it include your own?
Yes
Do cards have to appear face up in the void?
Yes
If there is a tie in the beginning, does everyone have to redraw?
Yes, unless all tied players concede that one person can go first.
Is there a maximum amount of life that a player can have?
No. If there are not enough life cards, you should use other items to count life (poker cards, dice, etc.).
Can a player battle even if they are going to lose?
Yes. This can be done to free resources, for example.
In battles, in the case of ties, who chooses whether to sacrifice or lose life first?
The attacker should choose first.