The idea of building Moria seamlessly, without being ruined is extremely appealing I must say. This time around as
@Finrod_Amandil said, we need to take our time and build a worthwhile project for moria. The first step will be to have a very detailed and ingenious as well as lore-accurate map. I think this thread could be a focal point for ideas that people may have about what kind of rooms there may be in Moria. Or remind us of what the lore says about what area.
My opinion is that the old moria wasn't interconnected enough. Tunnels must lead to anywhere, we also have to take into account that dwarves hold a significantly different culture. If you want to build Moria you have to understand the awe of dwarves for everything that relates to mining, craftsmanship and awe-inspiring fortresses of stone. They are troglodytes and artisans before everything else.
I remember that
@Thatruben had made a very interesting concept for waterworks in Moria, so that people could have running water. This is the kind of stuff we have to think about seriously. Our mind must be set in an engineer mode, what kind of genius idea would the dwarves have developed to ease their life in an underground settings.
And then, once we're done with this we'll have to set our mind to goblin-mode, their hatred for dwarves, their culture (or unculture), their habitats, how the two would have overlapped. How they would have dealt war.
It's a very complex process