Not that I appreciate the lame joke in the title, but I'll help.
Making Spells with Essence requires a source of the needed essence nearby, within range, ideally linked to the crafting altar using a crystal wrench. Neutral Essence is from a Neutral Nexus, which you have to fuel with liquid essence by getting either a source or flowing block of liquid essence under the 3x3 rune, up to 10 blocks below it(as a reminder to EVERYONE, the Neutral Nexus can suck up liquid essence from a flowing block that is 10 blocks below the nexus yet the source is at max build height in a pool, just as long as it can trace its way back to a source block).
If you have essence in the nexus(can be checked with a magitech staff as a reminder), then your nexus is ready to accept the power upon you flicking the lever on the bloody thing. Assuming everything is in range.
Also the Keystone GUI is for locking down a gateway. Some people think it's for forming "networks", but they are incorrect. Gateways always work the same way. Power a gateway with enough essence of some kind and right click the keystone receptacle to open a portal to the closest valid gateway. If you have locked down a gateway you can only access it by using a Gateway when you right click it with a Keystone set to the same code as the gateway is on; this same mechanic is valid for all keystone locks. Assuming it's in range, which isn't always true.
A Keystone has 5 slots on the edge for holding runes(y'know, the things made from cobblestone and then mixed with a dye of some kind?). Every option you can think of is valid; all empty included, and you can even use Runes of Debugging in this thing strangely enough. The GUI has a few buttons. The left/right buttons only work once you have saved at least two codes, as they switch between codes. Save does exactly that, it saves a code so you can load it easily. There is a text box for naming codes and IIRC a couple other buttons.
