1. Correct. It actually states, that its preferably a technique. So I would say, that its limited to techniques only, but also objects. But I haven't used it on objects yet, so I don't know if that would actually be approved of, or frowned upon, depending on todays standards.
2. Correct.
3. Correct. I mention that they can see it only for an instant, before vanishing. Could indicate a Genjutsu.
Now, let me hear your thoughts on our Secret Technique, Reality Marble;
(Hijutsu: Koyu Kekkai) Δ Secret Technique: Reality Marble
Rank: Forbidden
Type: Supplementary/Offensive/Defensive
Range: Short-Long
Chakra cost: 50
Damage points: 90
Description: Reality Marble is available for Katsuryoku Pledged rank members and above. This pertains a secret technique for underlings, as it have proved inadequatedly to be handled and oft lead to the death of the user. The user will bite his thumb, and sacrifice a propertional amount of chakra to the point that a small implusive wave is released from the user's entity throughout the field causing clothes to sway, and leaves to fall off the trees etc. A mere dramatic effect, but also the damage the user pertains to use the technique(-20). Through the blood sacrifice and chakra the Genkis from the Pure World will bond with the user and without hestitation immediately form within Impure World in order to fullfill his desire. Instantly as the summoner's call is heeded, the Genkis emerge as flame-like mirages before fully manifesting into physical form, or construct, resembling that of heavily armed soldiers and cavalry composing a peerless array of legendary warriors, clad and equipped with a different variety of weapons and the like. Upon the user's command, they take trot and cascade down upon the enemy in numerous waves. They prove efficient as they are capable of both transitioning between the tangible and intangible state, capable of moving through obstacles with little to no effort. Once their assault is executed the waves vanish one by one. There's a total of three waves. Can be used twice per conflict, once per battle. The user can't utilize Clan techniques of A-rank the same and following turn.