What is to be understood is that when the Quran speaks about Jews, it isn't necessarily speaking about all Jews. Sometimes, as in this case it might have been something mentioned by a Jew or a group of Jews (in that time and place) saying something that no Jew every would agree upon.
In the verse 9:30, we can quote from the answer to the question "What is the reason/cause of the verse in regards to Uzair?":
Tafsirs state that this was revealed in response to a specific group of the Jews who said this to the Prophet Muhammad(p.b.u.h) and was not a common belief, nor does it remain a canonical belief in Judaism.
I can also add one tradition mentioned in Tafsir Tabari:
كان ذلك رجلاً واحداً
It was only one man.
The second verse you mentioned is also explained in the answers to the question: In what way do people equate the scholars and monks to Allah according to the verse 9:31? It is also mentioned in Tafsir Tabari that the explanation for that is that some from Ahlu Al-Kitab (at least some in that time and place), used obey their scholars when they made what was haram to halal and made what was halal haram.
Basically Jews are mentioned in this verse:
إِنَّ الَّذِينَ آمَنُوا وَالَّذِينَ هَادُوا وَالنَّصَارَىٰ وَالصَّابِئِينَ مَنْ آمَنَ بِاللَّهِ وَالْيَوْمِ الْآخِرِ وَعَمِلَ صَالِحًا فَلَهُمْ أَجْرُهُمْ عِندَ رَبِّهِمْ وَلَا خَوْفٌ عَلَيْهِمْ وَلَا هُمْ يَحْزَنُونَ
Surely those who believe, and those who are Jews, and the Christians, and the Sabians, whoever believes in Allah and the Last day and does good, they shall have their reward from their Lord, and there is no fear for them, nor shall they grieve.
... where they are categorized as "whoever believes in Allah", this is clearly talking about monotheistic Jews. Therefore Jews are generally considered monotheists in Islam.