Newbie speaking (and because I wrote about viscosity earlier this week):
first, i agree, there should be a deterrent from keeping new players from having access to every scene. The pressing theme I have been getting as a new player is PATIENCE. And truthfully, that patience is imperative to understanding this game.
My biggest contention with viscosity now (as mp4) is that No Man's Land and Marind Bell (up to Wind's sanctuary) should be more accessible.
And although I agree an algorithm is called for to lower viscosity by a percentage per game level, not every player at each game level has achieved the same things so for me, that rationale is akin to assigning the same GPA score for a student that gets a 90% and a student that gets a 99%. In other words, if an algorithm is to be applied, it should be based more on player skill - say vital energy, value points, current AP, etc and not so much on game level.
I still hold to my original thought, that players should walk the scenes regularly. Perhaps it could be a quest or become part of the training to get to mp4; a way to teach new players that seeing all the scenes is beneficial to game progression?
I hope that my thoughts have at least some value even though I am new to this realm. Newness is not an indication of observation and contemplation. I haven't missed a day since I began the game and I talk to people in every scene.