Congrats on commuting and welcome to TE! We have a few guys who hang around, and most of us don't bite
We used to ride the open grate drawbridge at Wrightsville Beach all the time. The only problems were 1) when it's wet and 2) when it's really cold (and wet). Wider tires definitely help, and you will feel the bike move some under you. It's kind of unnerving, but so far I haven't fallen on it (I don't ride it regularly anymore since we've sadly moved away). Which bridges are they? There's always the possibility someone on here rides those roads and can give you more specific feedback.
My DH has this mirror: http://www.rei.com/product/605686 He's used it for a couple of years and has been pretty happy with it. Cons: I think you have to buy a new one when you replace your helmet, the mirror can come off and (with any helmet mirror) you have to adjust every time you put it on. I tried one, and got really motion sick from it (odd, I know).
Good luck!
CA
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