I only use cheat to see the finisher though, tried it on different save data so my 'true' play through won't get tainted by the cheat code XD
Yes I know that the character are themselves, they introduce themselves with their MS/Kamen Rider name, not their pilot/human alias after all; with the exception of W (they normally refer themselves as W, but then they also introduce Phillip and Phillip himself calls Shotarou by his name) ^^;
Birth here is DateBirth, by the way. He's cheerful (calling Cherudim Gundam as "Cherudim-chan", for example) and helping Celestial Being as their doctor, IIRC.
I found the video where someone edited some sequences with voice. It really makes the whole thing much better.
http://www.nicozon.net/watch/sm18745084 And yes, the playable characters wasn't that much, only 5 on each series.
Ultraman: Hayata, Seven, Tarou, Mebius, Zero
Rider: Ichigo, RX, Den-O, W, OOO
Gundam: Nu, Z, God, Wing Zero, 00
The rest of the characters are support, only give characters/enemy status effect as far as I know, not actual attack with 3D sprite like the playable ones :\