My concern with 'fruity flavors' is the molecular diversity. Many of these compounds are considered safe for human consumption (edible) but under-researched when vaporized an inhaled, which has the potential for formation of novel unexpected compounds, especially in heterogenous solutions.
I think the risk from these compounds is likely an order of magnitude less than the risks of cigarette smoking, and these risks will decrease as we get more data on longer-term use for these compounds.
I read one study that found benzene formation in vapor from higher-watt devices, but not in lower ones. I think using minimum necessary power is a good harm mitigation measure until more data comes in, that would likely help with flavors as well.
Seems like stringent labeling requirements for vape juice would be a cheap win for regulators and consumers. Give us an MSDS with the exact constituents.