I tend to agree with you that it may be best to have few bacteria in the small intestine.
My gut feeling is also that you are right about the relationship between Candida and SIBO. When I took ABx last year, I actually felt better for the first week, until the Candida overgrowth symptoms kicked in. Also, Candida can cause a leaky bowel, then having SIBO will worsen symptoms as the bacterial toxins leak through the gaps in the epithelial wall.