I concede the point on the Cut the Air ability.
Also the word "larger" is missing from Space-time: "The rift can be as large as one size category ^ than the Vorpal Warrior using this ability."
The rift can be one size larger than the vorpal warrior.
The Heads Will Roll ability isn't very clear. Normally, you threaten adjacent squares. Do you mean you now get an attack of opportunity from creatures that are farther away from you? For example would a Medium sized vorpal warrior threaten creatures that are 10 feet away (15 feet on the diagonal) or do you mean something else? Are you also increasing the critical threat range of her weapon?
Heads Will Roll (Ex): At ninth level, whenever a Vorpal Warrior wields her vorpal weapon, she gains the ability to threaten creatures that are not adjacent to her. A threatened creature must be no more than 5 feet beyond normal range. In addition, the critical range of her weapon to decapitate a foe is increased by 1; this stacks with any previous increases gained.