How do you get/find 'Trove' chests vs the current level 1-7 chests? Will the T-maps convert or something?
Are you talking about on TC, or when it goes live? On TC you can get the "new" map (different names) via a "clicky", for all facets and levels. You can also "copy" a character over (WHEN copy "comes back up), with a loaded Davies Locker (it took 1 day though before the maps were readable (after the next server up).
When it goes live the maps are supposed to convert like this (note, all maps have different names and loot):
Level 1's stay the same
Levels 2s and 3's COMBINE as a new level (2)
Levels 4 and 5 COMBINE as a new level (3)
Level 6's stay the same but become level 4
Level 7's stay the same but become level 5
This is a very brief overview, but gives you "basics".
So far, however, I am NOT impressed, at all, with the "new and better" loot.