worldly sciences

Q:

1. Is acquiring knowledge of the worldly sciences دنيوي علوم for example faradhul kifayah according to the Hanafi Madhab?

2. If so then a فرض is thabit by a dalil in which there is no شبهة i.e فطعي دليل . What is the qati dalil for this?

3. A منكر of a a fardh is classed as kafir. Will a person who rejects it be classed as kafir?

4. Will it be necessary to have belief of it being fardh? ( fardh's ruling is الزوم علما و تصديقا بالقلب)