There is absolutely hyphenation support - you can toggle it on or off in settings, but it is off by default.
regulation the circulation.
Bad typography is my main quibble with the Kindle app. It's been awful for years.Have you looked into a better flow algorithm, such as the Knuth/Plass [1] algorithm from TeX?
[1] http://onlinelibrary.wiley.com/doi/10.1002/spe.4380111102/ab...