Yes, summoning sickness can prevent a creature from attacking or using its abilities on the turn it enters the battlefield.
Summoning Sickness stops a creature from attacking, and prevents it from tapping as the cost of an activated ability that uses the tap symbol. Non-tap abilities are not affected by summoning sickness. They can be tapped for the cost of abilities that do not use the tap symbol (such as that of Gilt-Leaf Archdruid).
No, you cannot activate a creature's ability when it has summoning sickness.
Summoning sickness prevents a player from attacking or using the abilities of a creature that was just summoned. This impacts a player's ability to gain control of a creature because they cannot immediately use it to attack or activate its abilities on the turn it was summoned.
A Planeswalker can only use one ability per turn, and only on your own turns. Planeswalkers do not suffer from summoning sickness though, so may use an ability on the turn they are played.
No, not all creatures have hexproof in this game. Hexproof is an ability that some creatures may have, which means they cannot be targeted by spells or abilities your opponents control.
No, of course not. Summoning Sickness stops a creature from attacking or using an ability with a Tap symbol as a cost. It does not stop it from being tapped by other effects, or for certain costs which require a tap, but do not use the Tap symbol (they can be used for Convoke for example) and they are certainly not destroyed if they end up tapped.
To ensure that creatures you control have double strike in the game, you can use cards or abilities that grant the double strike keyword to your creatures. Look for cards with abilities like "grant double strike" or "creatures you control have double strike" to give your creatures this powerful ability during gameplay.
Creatures can gain haste in the game by having abilities or spells that grant them the ability to attack or use abilities immediately after they enter the battlefield. This allows them to act quickly and gain a strategic advantage by attacking or using their abilities before their opponents can react.
"Cairn Wanderer" is a Magic: The Gathering card with the ability to gain the abilities of creatures in graveyards. It has characteristics that make it versatile and powerful, as it can adapt to different situations based on the abilities it acquires.
In Magic: The Gathering, the keyword "haste" allows creatures to attack or use their abilities right away when they enter the battlefield, without having to wait a turn.
Teysa Karlov's official rulings in Magic: The Gathering state that her ability applies to triggered abilities of creatures you control, and that it does not double the effects of those abilities. Additionally, her ability does not interact with replacement effects or prevention effects.
One effective way to remove indestructible creatures in Magic: The Gathering is to use cards or abilities that exile them from the battlefield. Exiling a creature bypasses its indestructible ability, allowing you to get rid of it permanently. Cards like "Path to Exile" or abilities like "Banishing Light" can help deal with indestructible creatures effectively.