Is it not possible that Toei, Tsuburaya, Takara, etc. could peruse fanboards (anonymously or not) to get feedback on their stuff?
English-language forums? Pretty damn unlikely. Remember, Toei, Tsuburaya and Takara for the most part don't sell anything to us directly. Any money they see from Western audiences is either funneled through licensing fees from Adness, Disney, and Bandai or provided very indirectly through import purchase.
Toei, Tsuburaya and Takara are going to pay close attention to Japanese forums and fans, sure. They'd be stupid not to, that's their primary audience. We English-speakers are a secondary audience, though, and one that is going to have relatively little influence over a final product that we're not even supposed to be watching in its original form.
Tokusatsu is for the most part a commercial venture. The companies want to create successful products. But since they don't really sell products to us directly, they don't care about our opinion of the original. Now, our opinion of Power Rangers, Dragon Knight, and other Americanized products can matter, but even then we're a secondary audience because we're not little kids.
These forums are here for the amusement of the fans that post to them, nothing less or more. They're an utterly quixotic staging ground for any crusade to change tokusatsu. At best, you might change Dragon Knight or Power Rangers.