tl;dr - This is an unabashed
Femdom game for submissive players (think Monster Girl Quest or Darktoz's Asylum). The presentation and mechanics are fun, but ultimately if you don't want a bunch of scenes of the player-character being dominated, this game isn't for you.
In terms of length: following my guide (throwing fights to stockpile potions then attempting to win for real to rush the "Surrender" book) I think would take about an hour, more if you explore some of the scenes/traps/fights naturally or attempt to beat the harder difficulty versions of the girls (which has no purpose as far as I can tell).
More detailed Tag / Sex Scene info (Spoilers)
Pasting my own questions from the request thread in case anyone figures them out: