Almost every criteria you put forward is subjective, and the rest of what you propose (Conference, Observe, Remediate, Terminate) bears a strong resemblance to union contracts in many fields.
The problem is that management and parents never want to follow the rules that are laid out in the contract. Read the comments in this thread and you will see that many people are complaining about the fact that at some stage in a process similar to what you outline the teacher was found to be competent/compliant with the rules. People want to fire "bad teachers", but they want to fire them the second they themselves identify them, not wait until after there has been some verifiable non-subjective proof of wrongdoing or incompetence.
Any review or remediation will be called "bureaucratic obstacles" or "politics" by the people who think this is easy. See bad teacher=fire bad teacher, simple.
Never mind the teachers that would get fired because they tried to teach something that violated the parent's world view (e.g. evolution).
I'm sure every person in this thread who is in favor of abolishing tenure is well intentioned, but most of them have probably never found themselves unemployed at the age of 55 with a "bad teacher" reputation hung around their neck because the school board realized they could save tens of thousands in salary and retirement costs by firing a teacher that ran against them in the last election.
At least removing obstacles from the firing path will never lead to a world where teachers will be afraid to publicly complain about waste and corruption in the schools, right? Whistle blower laws are just another legal trick in the union's arsenal.
The teachers that are "bad" because they dared to tell a well connected parent that their precious little butterfly has no business being in an advanced class will sleep better knowing that they lost their job to save us from the scourge of easily identified bad teachers.