A would destroy deidara, raiton>Bakuton, he's too fast to be hit by any explosives, and c4 wouldn't affect him. People say that Deidara will outsmart him.. lol, his "fullproof plan" to kill Itachi was bombs that can be seen with sharingan... nice.
And everyone says there's no way to beat Pain without knowledge of the paths. But think about it, A could just blitz almost all of them.
Asura - blitzed the way Naruto did it.
Human - it has to get close to attack right? a would destroy it in a taijutsu battle. Naraka - blitzed.
Preta - I don't think it can absorb A's fist in it's face.
Animal - people say Cerberus solo's, The time it takes to put your hands on the floor and summon the animal is a good opening for A to speed over there and kick a hole in the paths chest.
Deva - I think that once he gets to this path and Nagato is focusing all his chakra into just one he could use the planet thing Chibaku tensei I think. But if he is just using his Shinra tensei and if A can figure out the 5 second interval then he might have a chance.
he would just fake attack, pain would use Shinra tensei and 5 seconds is plenty of time to get up close and Lariat/ Liger bomb
I don't think A can win against deva path or Nagato but I'm pretty sure he can take out 5 paths easy. Even if their eyes are linked they can't see him because of his speed. And none of them are fast enough to get out of the way.
As for the rest of Akatsuki, I think he can take everyone except Itachi, Tobi, and Kisame (maybe)