1. When you summon as a standard action, does the summon appear and act during your turn, or does it still come in just before your next turn?
2. Can you choose whether you use the feat or not? That is, do you HAVE to cast as a standard action and risk becoming fatigued or exhausted?
1. They would appear and act on your turn...technically after your "turn" but right then. The only reason they appeared and acted at the beginning of your next turn was the 1 round casting time.
2. That I do not know for sure by RAW. My GM is fine with someone choosing NOT to use a feat if they do not want to.
Can I get any corroboration on this? I don't think there is an official reply anywhere on this feat, but it would be good to have a few more replies to have a consensus.
Summon monster specifies that the creature acts immediately on your turn. Normally, the spell completes just before your next initiative count -- but you're speeding up the casting time to 1 standard action, so yes, if you cast the spell the creature acts without delay.
Acadamae Graduate is a 3.5 feat and may require conversion.
Read as written, whenever you cast a prepared arcane spell from the conjuration (summoning) school that takes longer than a standard action to cast, then you reduce the casting time by 1 round and make the saving throw. The text reads as a when-then statement, implying no choice.
Outside of RAW, I would allow a player to choose. They could take this feat at 15th level after a long career of summoning, and it would be strange if it suddenly made them incapable of casting spells normally.