i think there should be a place where you can post an app for an invention or creation to be approved by an admin or something. then (for a kido), you must also create a thread of a determined length where you actually create it and learn to use it effectively. as for an invention, probably the same with an invention, depending on the type (like if it's intended for combat). (also, inventions would be restricted to 12th Division members, and Arrancars who were a part of a research division in Las Noches)
for example:
Invention:
Name: All-Purpose Goggles
Description (include how it works): The goggles are a very high tech piece of technology. First off, they are pretty damn hard to break, able to withstand extreme temperatures at both ends of the spectrum, blunt force up to 150000 Newtons, being submerged underwater indefinitely, and electrical/acidic/weather/etc damage. They provide the user with some very nifty abilities. The more basic functions include night vision, x-ray vision, and infrared. Its more advanced functions include being able to a) analyze any piece of machinery and break it apart into blueprints for the user to better understand, and b) see and analyze reiatsu particles (basically grants the user Urahara’s keen observational skill).
Application: Being able to see and analyze reiatsu particles is great for learning, and also good for a skilled user who can manipulate his own reiatsu in such a way to directly negate whatever reiatsu attack is aimed at him.
Restrictions (if applicable): None. Pretty useless for a comparatively unskilled user though.
They look like an engineer's goggles
http://blog.martincrownover.com/wp-content/uploads/2008/12/tf2_engineer_closeup.jpg
or
Name: Reiatsu Shield
Description (include how it works): The device consists of a lightweight molybdenum steel alloy bracer with an electrical power source, a focusing crystal, and a magnetic field generator. The way it works; the user runs a minimal amount of reiatsu through the bracer, which triggers the power source. The resulting energy is sent through the focus crystal, which splits the energy into protons, neutrons, and electrons. The magnetic field shapes the electrons or protons into a circular field in front of or surrounding the user. To put it simply, the Reiatsu Shield takes the user’s reiatsu and shapes it into something useful.
Application: The shield can be used to repel anything made of metal with limited efficacy. Weaker attackers will not be able to best the strength of the magnetism repelling their blade. It also provides excellent protection against energy based attacks such as kido and Cero.
Restrictions (if applicable): Because the shield relies on the user’s reiatsu to function, the more powerful the user, the more effective the shield is. For example, a Vice-Captain would not be able to stop an Espada’s Cero with the shield.