Yes, you can chain to a card(s) that activate during the Standby Phase.
Standby phase is in a yugioh duel after draw phase,you could use card effect at standby phase.
In your own standby phase, yeah. It is a Quickplay spell, so can be played from hand in your own turn. You can draw it, then activate it in the Standby phase, tributing Treeborn Frog, then resummon the frog before the standby phase ends.
Yes, it will. Both effects happen 'During the Standby Phase'. You will return the Fortune Lady to the field during the Standby Phase, and then it has its own effect waiting to be applied, which will increase its level when you do so.
Yes, of course. Exactly the same as main phase 1.
Yes, as long as it is Spell Speed 2 or 3, and Set on the field previously in the case of a Quickplay Spell or Trap card. That means the opponent can potentially do something before you get your first opportunity to activate a spell speed 1 card or perform a summon.
Game phases? If you mean the phases for a turn in Yu-Gi-Oh then here they are: Draw Phase Standby Phase Main Phase 1 Battle Phase Main Phase 2 End Phase
Unfortunately, no. The offical website says in the Individual Card Rulings section: If you Special Summon "Treeborn Frog" during your Standby Phase, then it's sent to the Graveyard during that same Standby Phase (like if it's Tributed for "Enemy Controller"), you can Special Summon "Treeborn Frog" again that same Standby Phase. Otherwise you could draw through your entire deck! :D
No, it doesn't end the battle phase.
Since DD Sprite can only be summoned during your own turn, its trigger will activate in the opponent's Standby Phase.
You can use it during the Battle Phase, but not during the Damage Step of the Battle Phase. So if you attacked, and an opponent used Mirror Force, then you can chain Trap Stun, as you are not yet in the Damage Step. However if the Damage Step was entered and a player used Nordic Relic Megingjord, you could not chain Trap Stun to it.
Yūgi-ō sutanbai-shō
It lasts every end phase.