Cleaning up chart of accounts

We are on release 8.10

I don't think we have ever done a lot of reporting based on LOD

We want to clean up our chart of accounts and streamline the LODs we have in place.

1) Knowing we don't have reports that rely on LOD now, is there any harm in changing LODs as needed?

2) If we update our model, is there a global update function that would update all the LODs ?

3) in the 8.10 manual, on page 34, they talk about a Structure Tree View..... how do we get to that to review?