Such a person can be described as:
Always right
A critic
A faultfinder or a critic.
The word "scapegoat" is sometimes used in that sense.
Self-opinionated
Noisy.
kiss me
Inquisitive
Independent?
Ask your friends, co workers and neighbors who they use. It is always best to have a recommendation by word of mouth. This way you know you have someone reliable and someone who does a good job.
No, you do not always need to put a comma after the word "so" if it is the first word in a sentence. It depends on the context and flow of the sentence.
Predictable: someone who exhibits behavior that is expected.