Menachot 9: Mixing the Meal Offering: in the Temple? By a Priest?

Based on our last Mishna, Masechet Menachot considered the handling of the lechem ha'panim, translated as the shewbread.  Daf 8 described what what flexibility there might be regarding the ingredients of the meal offering (fine wheat flour, oil, frankincense).  

Today's daf considers where the holiest items should be consumed, in the Sanctuary on in the Temple courtyard.  At the end of today's daf, the conversation turns to the rabbinical thoughts on removing the meal offering with one's right hand only.

In one case, Rabbi Yochanan declares that a meal-offering prepared with less than perfect precision is invalid and Reish Lakish disagrees.  He notes that in Vayikra (2:2) the oil and frankincense are added to the flour before the priest takes the handful to be sacrificed on the altar.  Thus the preparation does not require a priest and it need not take place by the Temple.  Rabbi Yochanan counters that we know that the meal-offering must be mixed by a kohen in the Temple because it was placed in a vessel only used in the Temple.

Tosafot argue: based on the later Gemara conversation (daf 18a), if the meal offering are placed in the keli sharet, the Temple vessel without having been mixed, the offering is still valid.  So how could Rabbi Yochanan argue that improper mixing is more problematic than no mixing?

Reish Lakis says that there is an argument against the statement that because a priest needs not prepare the offering, then it need not be done in the Temple. Shechita, general slaughtering, can be done by anyone but it must be done within the Temple courtyard.  In the writing the Chazon Ish, we learn the basic difference between shechita and mixing the meal-offering.  Mixing the meal-offering is less important than shechita.  It is only considered to be significant if it were part of the priestly service.  This proves that mixing need not be done by a priest nor need it be done in the Temple.