Docking station is absolutely good idea, for device that doesn't have normal USB connection. Furthermore, You could add 5V 2A fuse to 5V line, and diode preventing reverse polarity (elements, that are lacking while using pads beneath battery) - without worrying about their size. (would be incorporated into docking station).

Of course, using station, You don't have much chance of situation, where fuse would save You - but, adding it, is negligible work, compared to rest of station building. Other than that, you're not missing any elements - sure, no external ESD protection for USB lines, but chip have internal ones, rated for 8,8kV. Should be sufficient, if You're not planning to catch lightning strikes with Your device

Despite of what some* claims, it should be no problem I know people, who are using pads under battery as everyday way of connecting USB (in environment without any anti-ESD "safety thingies"), for a year already, without single problems.

/Estel

*mentioned "some" should be knowledgeable enough, because "they" are e. engineers - although, with all due respect, real life > e. engineers experience, so I wouldn't be worried about it.