Yes.
yes. it also beats any "3 of a kind"
ace wins
ace beats all
An ace-high straight flush, otherwise is known as a royal flush, is beat only by five of a kind. This is only possible in games with wildcards.
No. Four-of-a-kind does not beat a flush of any kind.
yes
It depends on the game. Which cards 'beat' others will be defined by the rules of the card game, whichever it is. Many games do not use the joker at all. Others, such as Canasta, treat it as a wild card. In Euchre, it is the highest ranked card.
No.
yes
No, Ace is the highest card in the deck and a two is the lowest.
A Royal Flush Is the strongest hand in most poker variations that do not include wild cards. It consist of a five card sequence of Ace, King, Queen, Jack and Ten all of the same suit. For examle Ten through Ace of hearts.