There is no one factor you should be worrying about. Or, the corollary: nobody can tell you one, or a few things you can do that will magically make...
Not necessarily. But you don't know anything about the wood you've got on hand, other than that it's lighter than what you used before. And the side...
Ok, what does "darker tone" mean? To me it means, as a gross over-simplification, "Set the EQ to Bass Boost".
So if you want it to really have those...
I've only ever had to adjust truss rods on customer's mandolins if the customer (or someone in the past) messed with it or broke it.
So I build mine...