Counters will cancel out and be removed, but actual cards will not (they effectively cancel out, but they do not get removed unless other cards act specifically to remove them).
This is a state-based effect, which means it happens faster than you can tournament legally react to it (you can react to cards or effects that try to add one of the counters, but once the counter effects the card you cannot do anything to stop the cancellation).
People use this rule to keep creatures with "Persist" in play longer than they normally are.
An Ooze token is a creature that can be created. The token card is the representation of that creature.
No, unless they have haste.
'Flash Counter' is a Blue Instant costing 1U. "Counter target instant spell."
Yes. The card never leaves the field, it does not lose any enchantments, nor do equip cards unequip from it, nor are any counters lost.
A giant deck is a deck consisting of the creature type giant.
'Casting a creature spell' means to pay the mana cost and put the creature spell on the stack. If this is allowed to resolve, then the creature enters the Battlefield.
Whenever a creature with lifelink deals damage, (combat or otherwise) to a creature or player, you gain that much life.
it means if the oppdent is making a speel you can counter it and send it to the graveyard before they use the efect
Single cards that represent a creature (token) there are currently 199 that I am aware of.
If creature has Reach, it can block flying creatures without having to have flying itself.
No. You cannot kill the creature that is sacrificed in reponse to it being sacrificed as it is already gone.
If a creature has Intimidate, when it attacks, it can only be blocked by creatures that share a colour with it, or artifact creatures.