No$gba 2.7 does not exist...what you have is some lame unofficial hack. Yes No$Zoomer really needs version 2.6a, that version is however currently ethically unavailable as it's the donate-to-get-it-early version and donations are down and have been for some time so I am afraid you're out of luck.
And no there's no wifi in any DS emu.
As for the mic, it works perfectly in some games and not at all in others...something which can also have an effect on how well the mic works is how well the game is running, if's running slower than perfect then no$gba can't correctly interpret whatever you're trying to do with the mic.
No, there's pretty much nothing you can do improve performance, you can increase frameskipping and turning some things off is rumoured to give you a little more performance but NOTHING will give you a magical speed increase, nothing will make a game playable if it's not already so.
And no there's no wifi in any DS emu.
As for the mic, it works perfectly in some games and not at all in others...something which can also have an effect on how well the mic works is how well the game is running, if's running slower than perfect then no$gba can't correctly interpret whatever you're trying to do with the mic.
No, there's pretty much nothing you can do improve performance, you can increase frameskipping and turning some things off is rumoured to give you a little more performance but NOTHING will give you a magical speed increase, nothing will make a game playable if it's not already so.