A Question About Constraints

Try to think of it as a design question and not a constraint question. Does XYZ need to occur in a certain amount of time or it won't work. If so, what is that time?

For LEDs, it shouldn't matter. If it takes 5ns or 50ns to get to them, no one will notice, so leave unconstrained.

For the reset, it depends. If it's coming in off chip and from an asynchronous source(say a pushbutton), then there is no way to constrain that because the source is not synchronous to the destination. Lots of users synchronize a signal like that(have it feed 2-3 registers) and then have the output of the last register drive your logic. That can be constrained and will be just by the nature of your clock constraints.