which Mazhab

Sir my question is me and my father have been following hanafi madhab, but after reading alot of ariticles and gaining knowledge on various problems, now I feel that hanafi mazhab has adopted more strict point of views on various problems (masyles) where hanafi ulema have done Ijtehad. My question is;
a) is there any Ahadis or Ayat which bind us to follow one imam or school of thought as we have now a days, like Hanafi, Shafi, Malaki and Hanbali.
b) If so which madhab should we follow and what should be criteria and If we have two options for one problem, like we have hanafi fatwa and we have shafi fatwa on one problme, one is easy to follow and other is difficult, which option should be followed easy or difficult.
d) Will it be a sin if I feel to understand and follow some problems from Shafi point of view although I am Hanafi.
e) why there is 180 degree difference of opinion on one problem by hanafi and shafi or hanmbli or maliki fatwa. Like Hanafi says donot say Allah is on Arsh and there is no direction for Allah where Shafi say Allah is on Arsh whereas it is proved with Ahadis and Quran that Allah is on Arsh. At the time of tahweel Kaaba, our prophet was seeing towards sky again and again and Allah mentioned it in Quran. Some times really it disturbs alot that why these ulema give Fatwa 180 out of each other.
May Allah give you alot of Ajar on resolving above problems
thanks indeed.