If there is anyone out there of whom had purchased the early beta of Divinity: Original Sin via steam, could you answer me the question of if the Co-op on steam utilises Steam servers?
Yes they have matchmaking through steam and via Lan and Direct IP connect.
There is no shame in how this was designed. It is far from being a mmo in terms of a lot of people in the game at once. It's just not designed in any way for that. But think of me as an old-timer, we went from SP RPG's to a couple of Coop RPG's, then bam to almost every multiplayer RPG a mmo with nearly identical mechanics.
The coop RPG was forgotten, though imo was never shunned by players but by developers, chasing $$$ of subs and transactions. They weren't game designers they were driven by reoccurring dollars and little else. Funcom, Nexon, PerfectWorld, NCSoft and more. All they are making are games in which they hope they can bleed your last penny, they don't really care about awesome gameplay. They can't make a game unless it can have a reoccurring revenue stream, because that is the only thing they are aabout.
IMO a desktop PnP game is small coop group, turnbased RPG. There is almost none ever made. That is the shame, not that this isn't a MMO, but there are so very few of these ever made. Perhaps you should rethink, that you are getting a unique gem here and if you want a MMO, go to MMORPG hit Game list you have about 1000 of those, 990 doing the same thing. I'd say DDO is the best that genre has come up with.
Hopefully the next gen of "build your worlds" MMO's will give us some new life, like EQ Next.