Sentence2: I am a fast-learning and self-motivated person.
Sentence4: I am fast-learning and self-motivated.
The last one is difficult because teamwork is usually written as a noun without a hyphen, and I've never heard it used in adjective form (although anything is possible!). I would probably rewrite to say:
Sentence6: I have good skills in problem-solving and teamwork.
I'm interested to see what others have to say.
Student or Learner