The Talmud (Gittin 56a) relates the following about the Zealot-Pharisee relationship:
The biryoni [presumed to be Zealots] were then in the city. The Rabbis said to them: Let us go out and make peace with them [the Romans]. They would not let them, but on the contrary said, Let us go out and fight them. The Rabbis said: You will not succeed. They then rose up and burnt the stores of wheat and barley so that a famine ensued [...]
Abba Sikra the head of the biryoni in Jerusalem was the son of the sister of Rabban Johanan b. Zakkai. [The latter] sent to him saying, Come to visit me privately. When he came he said to him, How long are you going to carry on in this way and kill all the people with starvation? He replied:
What can I do? If I say a word to them, they will kill me. (Soncino trans.)
This passage clearly portrays the Zealots as being responsible for mass starvation, and clearly aligns them against the Pharisees, and their leader Rabban Yochanan b. Zakkai. Their military struggle against the Romans was viewed as doomed to failure, and the Pharisees considered diplomacy the only viable solution.
This approach seems to have remained accepted among later rabbinic thinkers such as R. Ovadiah S'forno (16th century) who in his commentary to Genesis (33:4) notes that were it not for the "baryonim" [Zealots], the Temple would not have been destroyed.
Regarding the murder of a high priest, this website states that Antiquities (20:162–66) relates that the first victim of the Sicarii was Jonathan (b. Anan), who had previously been high priest under the influence of the procurator Felix, who was interested in getting rid of Jonathan. Interestingly I have not found reference to this in rabbinic literature. (I haven't looked that hard).