As long as all conditions for NMI are met (including probe connection and probe spread), a current can flow through muscles and the attacker can lose control of said muscles.

Each cartridge can only be fired once but can deliver multiple electrical cycles. That means that while the darts can only be projected at a target once, as long as the darts remain in the target after the initial 5-second electrical cycle, subsequent electrical cycles can be engaged.

The darts can penetrate clothing and the electricity can also jump up to two inches of combined distances between the probes and the skin.

No. However, the batteries are user replaceable and provide enough energy for many uses. You can find a TASER X26P replacement battery here.

As probe connection and probe spread are the primary conditions for NMI, a probe deployment's ability to induce NMI does not depend on the target's mental state.

Other than the length of the cartridge that is available to consumers, the civilian X26P is 100% identical to the Law Enforcement grade X26P.