Indeed, as stated above the plot has a foundation, which is really the most important part. Building upon that is half the fun right? And the mechanics well need to be cemented and chiseled in stone. Mostly because the Shin Megami Tensei and Persona games, are interestingly and oddly not your standard RPG fare. In that respect the odd juggling between dating sim/ dungeon crawler/ JRPG will be an interesting mixture to say the least. So as Fox has stated making sure those are firmly cemented and all the RPers are on the same page about them will be probably one of the most important things. 

Though I do say, I do like the idea of the Bond system. Kind of like social links, but less having to worry about reversing them. Seeming to move more along the idea of the Friendship, Rivalry Systems of DA2 the only somewhat effective feature they added to that godforsaken game.