If it's been in the tank for a month or more, it's live. LR
refers to the rock housing beneficial bacteria. They attache to the surface of the rock. As rock used in our tanks is very porous there is a lot of surface area for the bacteria to colonize.
A power head is generally a good idea. The general rule is to have 10x -20x tank volume in water flow through the tank each hour. So a 26 gallon tank should have 260 gph
or more of flow from all sources. LR
is an obstruction to flow so more flow would be needed.
Another general rule is to have 1½ - 2 pounds of LR
per gallon of tank capacity to act as your biological filter. That with a good protein skimmer negates the need for a cannister or other mechanical filter.
There a quite a few threads on tank moves. Basically you need to set up the new tank. Get your substrate down (don't re-use more than a few pounds of sand from the old tank), add more base rock, then move everything over. That's a pretty simplified version.
Check with your LFS
to see if they will offer you any credit for livestock you may want to return. Each store sets their own policy.