Son? Eh, maybe.
But Jews do refer to God as 'Avinu' (Our Father) in a number of different prayers, so I'm not sure how 'radical' it would really have been.
Hence, I argue that the portrayal of the Pharisees in the Gospels stems from the anti-Jewish bias of the Gospel writers. This bias resulted from the fact that few Jews converted to the new religion and that the writers needed to differentiate Christianity from Judaism in order to gain Roman and Greek proselytes.
This is a Christian thing. Jewish law deals only with what individuals
do. Essentially, having a bad thought isn't sinful unless you act on it. That said, bad thoughts can certainly lead to sin, so mindfulness is important as well.
Protecting human life trumps every other mitzvah. If a person is sick, ill, dying, etc. Jewish law commands one to get them to a doctor, even if it means driving.
Not going to get into this one. Ritual purity is a complicated subject.
Well, there are plenty of reasons why Jesus isn't the Mashiach, but that discussion may be better performed elsewhere.
This isn't a Christian thing. The Pharisees in general (Jesus included) at that point in time tried very hard to get the Gentiles living among them (e.g. the Samaritans, other non-Jewish ethnic minorities) to be Jewish.
Well, there were some things that probably changed. Pharisaic outreach efforts being one. Generally, in Judaism if something obviously wasn't working, it gets changed. That said, there's no power structure in Judaism, so while the Pharisees were at the center of it (as are Rabbis today), we can infer that lay Jews were also very much involved in the process.
Not really. Depending on how you read the Mishnah and how much of it you read, it could be read as confirmation of the Gospel portrayal.
Not really. The Mishnah and later on the Talmuds (both of them) are at their heart redaction of rabbinic discourse. A topic gets set, and the laws about it are discussed. Generally, for any given thing, there's three or four opinions.
For example, the first mishnah of the Mishnah is Berakhot 1:1. It discusses the evening
Shema, particularly when to say it. All of the rabbis give their views. The questions are basically open-ended and anyone allowed to develop their own answers.