The two prinicpal writers on the show are
Yonemura Jôji and
Inoue Toshiki, both of whom were the replacement writers on Hibiki. Yonemura is also the screenwriter for the Kabuto movie, but aside from that the only Tokusatsu credits I know of are Sh15uya. He has done a couple anime though.
Of course everybody knows Inoue was the main writer on Agito, Faiz and the second hald of Hibiki, and he was also a writer (though not the main one) for Kuuga, Ryuki, & Blade. He's also done all the movies since G4 (except for the Kabuto one) including FIRSTy. And was the writer for the Kamen Rider SD OVA! In addition, he has quite a number of Tokusatsu writing credits, but being Igami Masaru's son will do that to you.
As for the ending, I'll say this: As much as I want it to rock, it'll probably be like the last couple of endings and be good, but not great. Major plotlines will be wrapped up, there will be some good fights, not every last mystery will be explained (because they rarely ever are) but when all's said and done, it'll just be another Rider show to add to the pile. So it won't be a flop, but it won't be like, the end of Stronger or anything.