Liquid yellorium is the fuel that is meant to be inside the reactors fuel rods. Outside of the reactor it is absolutely useless and can't be transferred into a reactor.
It does not matter which side you output the power. I personally use the bottom face most of the time so I can have my waterwheels adjacent to each other.
You can use any type of fluid pipe/conduit to get liquid into and out of a smeltery. My advice for getting Liquid XP into a smeltery is to use an item from EnderIO called a experience rod. When you shift right-click on any tank like a smeltery drain you store as much experience as the tank can...
There is an item in open blocks called the /dev/ null. It is crafted with a cobble and an apple and can hold a stack of a single item and void any further pick ups
Those planets and rainbows are from botania. However, I was under the impression that this was only supposed to occur in garden of glass (Botania's skyblock world type).
you can use regular sugarcane with mfr, however, you will not need a planter it will automatically harvest any extra levels of sugarcane with the harvester alone