Doubt can just be a matter of needing more knowledge. Like letting someone go cause of reasonable doubt. More knowledge can very well convict a person. I could have faith I made the right the decision, but what i choose to believe i up to me when it leaves the realm of knowing. One can also just choose not to invest faith until more knowledge is attained, like what your saying but that isn't investing in a belief.
I can't understand why love can't be based on reason. I do understand emotions aren't always reasonable but doesn't always have to be. Just like fear, fear can be for a real danger or an imagined one. Love doesn't have to be based on something imagined.
Emotions aren't always by choice, I understand that, as they are not always rational per se. But beliefs aren't always based on emotions and if they are then there is some sort of self delusion involved there. Love has reasons otherwise it is just some magic spell, we constantly have internal dialouge it isn't just butterflies in the stomach, there is thought process and decision making.