Thank you for your question. Remain true to your intellect and your heart and there is no doubt that God will guide you to what is right akhi. As for the Shia they choose to follow the Imams because they were the best examples of the lofty ideals of Islam and their relationship with the Prophet (saw) was on a completely different level to the other companions surrounding him (saw). Their moral character, spirituality, knowledge. If you read through the reports of what they said and the stances they took that should be enough to convince a person of their merit.
The Shia believe that the Prophet (saw) appointed Imam Ali (as) due to many authentic traditions as well as a rational position that the Prophet (saw) would not leave the Muslim community without a leader after his death, especially with the tumultuous circumstances leading up to his death.
May you always be successful.