I. Actually, I was saying that the remakes could be made using less time and development than normal main-series games and in that they could produce more in a short-span of time while making main-series games as an important part doesn't really exist in the remakes: Developing the Vast Pokemon featured in the region. They would only have to convert a past-game into a 3D World, Add some Megas, a Story, and a few finishing details (Sure this is embellished, but the point that it is less time-consuming by a noticeable margin remains nonetheless, evidence of this is that the release date is coming rather soon after a pokemon game had been released just the prior year.)
II. Yes, there are 'all sorts of ways to make pokemon available', Poke-Safari, Regular Routes, etc. But the pokemon list is always growing, and is rather vast presently, and to make all pokemon available shortly within the next few games would be a bit straining; regardless, it can be achieved over the course of multiple main-series games which I believe will eventually happen, as you say with other ways to make pokemon more accessible, but right now a lot have low-accessibility. With this, making 'remakes' of the past generations would then allow pokemon to have more accessibility (including past mascot pokemon, trios, duos, etc.), while also providing pokemon with a more expansive list of games on the 3DS Console.
III. Sorry for the confusion, Mitja. I'm suggesting that third versions will come out after remakes or main-series games do, but not until Gamefreak has "brought pokemon up to date" with mega evolution. In Kalos, we were able to get three Kanto Starters, sure, those pokemon are up to date. But there are other Kanto Pokemon, other Kanto Features, and more Megas waiting to be found within that region, and other regions for that matter! Making third versions after they have made progress on uniting the past generations with the current matters using, Main-Series games (as your solution) or Remakes, they may push out a third version game.
You also address the lack of Third Version features when we look at past Emerald, but how they execute the Third Version may not have rhyme or reason to the prior Emerald; it could take place years after ORAS (Akin to Black and White, and Black 2 and White 2), it could add new features (Similar to Join Avenue and the Theater Contest), it could expand on features already within ORAS, and it could come with more pokemon available. Pinning down a rigid view of a third-version remake seems a little too restrictive; possibilities for it remain ad infinitum, and we have yet to see the features in Omega Ruby and Alpha Sapphire and know what could be expanded on or their otherwise intentions for the game.
IV. It will remain useful, I agree with you. Although, its usefulness is like looking through a blurred image; the more its demand increases, the more it seems the 'usefulness' increases. Releasing remakes, releasing pokemon, etc. would then appeal strongly to more players of the game and as the vastness of the pokemon they can obtain
presently within the 3DS games increases, so would the desire to carry these pokemon over. This will accomplish its intended goal, reconnecting the past games to the future in bringing over other pokemon. It may seem off-topic at first glance, but I'm trying to iterate by bringing over remakes they bring over pokemon who players can get attached to and want to bring-over again, such would be the case with Emerald: People want to import pokemon from emerald, people want to export pokemon to Emerald. As they release new pokemon (maybe pokemon featured in Emerald to perform a new way of accessibility rather than 'remakes' as you suggested) people would want to carry those pokemon over and it remains a part of the motive that I perceive to make these remakes, third versions, and appeal to the nostalgia of the fan-base while also bridging together the new component of pokemon, mega evolution.
V. I remark upon the motives, Mitja, for a third version which would be 'Emerald'. I believe that Gamefreak may make a third version which will appeal to 'nostalgia', which are essentially remakes' primary component. GF goes make nostalgia-fresh games, but it also appeals to nostalgia from time to time, in a new pokemon era where people are unsure of the direction pokemon is going; it may be reasonable to make remakes, third versions, etc to bridge the gap between those people while also adding a new adventure into play.
VI. I think I answered your question with my above reason.
VII. Not quite, but I'm sorry if I was a little misleading. I'm implying that they will remakes and main-series games together, and once they have finished making remakes they could simply add a 'third version' like Emerald to continue where ORAS left off and versions who act similar in that regard.
VIII. It will be useful, sure, but I addressed this point earlier and that just because something is useful doesn't mean it's an automatic buy for many. By illustrating its usefulness over the course of more games, which means more pokemon to transfer over, exporting to and importing from Emerald, etc. The demand will increase and therefore more people will want to buy rather than go region to region fresh while leaving their old potential pokemon behind.
It's, simply put, a motive for making remakes which extends to the third version.
IX. That point proceeds to prove my point about these remakes, in the future generations the possibility for more remakes arises along with main-series games which are a staple of pokemon and I don't think would vanish from the scene but rather be made while remakes are also being made. "In that dream of generations, what games may come? Thus, speculation makes over-thinkers of us all."