"Ryuki" would've been better if the Mirror Monsters actually felt like threats, the story was explained more, and they gave the creatures more personality.
How were they not threats? You have monsters who are completely undetectable to anyone who is not in tune with the Mirror World, and can abduct you at any moment. The average person aware of the continuing disappearances would have to avoid any reflective surfaces to keep from being the next victim... and he wouldn't know about the the Mirror World, so that wouldn't happen. Of course they are a threat.
And I think monsters that don't talk and behave more bestial can sometimes be more intimidating than the ones who're always yapping.
"Decade" would've been better if Decade himself wasn't a walking ball of 'the best at everything,' Narutaki actually played a role that was explained (as an alternative Decade would've ruled), Kuuga actually used his Henshin, and the entire idea kept away from Showa Riders and villains.
I was initially against the Showa stuff too, but in retrospect it could have worked. It'd be sort of like the Marvel and DC reimaginings of established heroes and villains, or like how different movies can have the same characters (eg: Burton vs. Nolan Batman) but be unrelated to each other.
Decade would've been better were it just a straightforward "save the multiverse" story with the casts from all the Heisei shows, not just Hibiki and Den-O for no reason, brought back. The first half would be world-hopping and the second part would be the Dai Shocker reveal and team-ups with guest-appearing Heisei Riders. Then the movie can be all the united Riders in a final stand with Dai Shocker.
Other than OOO and Fourze with their multipiece set up I wouldn't say it's been that bad.
With Fourze though the Switches are pre-inserted, so you don't need to fiddle with them to transform, unlike with OOO. Also with Fourze swapping Switches is easy; with OOO the Medal swapping is more cumbersome.
I do wonder though why Gentaro never just flipped all the dials on his belt at once when transforming. He always did one at a time.
We'd have evil riders as the enemy and some riders will team up with Ryuki.
That more or less happened near the end. The surviving Riders formed alliances against each other.
Shinji being a newspaper reporter sucked
Why? It helped bring the third party (media/police) into the story. Too many superhero stories seem self-contained; other than the main players the world has no idea anything is going on. It's one reason I really like Kuuga through Ryuki; public awareness, which allows the hero to better act the part.
- Kabuto: If the Worms had a queen like the Orphenochs have a king, they'd be the real bosses of Kabuto instead of the Native.
The Executives were the Worms' bosses. The Natives were a separate group allied with ZECT. However, I did think that Dark Kabuto, if he was to be in this show, should have been the "Worm King" that ZECT was experimenting on and the Executives wanted freed, instead of some... nothing.