Who determines that the Mincha must be performed specifically by a priest?
The verse 'and he shall take a kmitzah... and burn it' teaches that from the kmitzah onward, the service is entrusted to the priest, unlike some preparatory actions.
Question 2
What is the ruling if even a small amount of oil from another Mincha or mundane oil falls into the Mincha?
Rambam rules that even a small amount of foreign oil invalidates the Mincha.
Question 3
What is the power of the tzitz of the High Priest regarding a kmitzah that has become impure?
The tzitz atones for tumah, so a kmitzah that became impure and was offered is accepted bedieved, but not for invalidity due to leaving the courtyard.
Question 4
How is a vessel with a divider at the bottom treated?
A divider at the bottom is considered a substantial separation of the vessel, so one should not take a kmitzah, and if one does, the Mincha is invalid.
Question 5
What is the ruling when a kmitzah from one Mincha mixes with a kmitzah from another?
Since both kmitzot are intended for burning, they can be offered together and the sacrifice is valid.