Yes, we're finally getting to the good stuff now. I'm suprised and glad that somebody thinks my idea is interesting enough to further question me about it.
If CV I-III were to form their own trilogy, how do you think the transition should be handled? You're taking three of Konami's most loved games and essentially removing them from the canon storyline (= retcon, in a way). Not so many people would like that. I'll also add that much of IGA's timeline was created to accommodate and build upon these original titles; by cutting them out you'd be removing one of the continuity's more important foundations.
Hmm, I'm going to try answer that question like I were the producer of the series.
First of all, I would make clear that Castlevania is not one storyline. It's a collection of stories that all share a similar world view. They all draw from the same well of accumulated assets (music, enemies, areas), but the details can be filled in by developers as desired. I would emphasize all storylines are equally as valid. Secondly, I would explain that treating CV1-III as a stand alone continuity would be following the original intent of Akumetsu's team (they created all three games). Thirdly, I'd argue the offical timeline was never supposed to be published and that it was leaked (I can provide the source), meaning it was originally supposed to be kept hidden so it could be revised as many times as the developers saw fit. Lastly, I would point out the games never really fitted well in IGA's canon, and that removing them would fix some continuity issues.
I would then proceed to publish a revised chronology in a guidebook, on the offical website, or perhaps as part of a pre-order bonus (whatever would be the most convenient at the time), putting my movation containing the above mentioned four points at the beginning. Alongside the revised IGA continuity, it would also list the CVI-III and Lords of Shadow canon.
Should anything be added or changed from the original games to make them fit better as a trilogy? How would you suggest optimizing them for their new status?
Personally, I wouldn't change anything about them. I would stricly follow the original intent: Dracula is Vlad Tepes, he became a vampire because of a devil pact, etc. It would probably be important to explain Trevor and Christopher are the same character in this canon to avoid any confusion. Though, this may be or not be original intent also. For the sake of the discussion, I'm going to assume that it is.
I'll address your third question tomorrow.
