CONTACT is instantly broken by DRAW or PUSH on either party (preventable with NULL/IMMUNE but never with VOID)
Simultaneous PUSH and DRAW from the same target is resolved by moving at a constant distance orbit around them
FALL body part can change (can roll, etc.)
DISARM on an arm not holding anything can still affect a weapon in the other hand
After DISAPPEARING, you can still make calls associated with things you set up earlier (eg. traps)
APPEARING is still subject to the 1 second rule, so after making it you need to wait a second before you start attacking someone
Calls from GAIN are consumed before any other sources of the same call
MASS calls cannot inherently be reduced to an ARC
If an ARC call doesn't specify a particular angle range, an ARC -can- be enlarged into a MASS
Other than using your own hits as a resource for some abilities, effects which cause loss of the other type of hit to the current plane you're in are very rare. Player characters will never get abilities which do this.
SAP on a character doing SINGLE reduces them to ZERO
RANGED DISARM or LOCK never get to specify an additional target beyond the person you're calling it at
FREEZE is a worse affliction than choosing to focus on resisting an affliction. With both it and any particularly horrifying EFFECT calls it is not in any way cheating to concentrate on resisting completely.