I use Bartender[1] for ~the same purpose. I love the idea of a minimal menu bar there's just too much stuff I might want to check occasionally.
So Bartender just shows me my time tracker (important for client work), Fantastical (I could probably ditch this) and battery status; everything else is in the hidden Bartender draw until I need it. Just one hotkey away - I bind it to Hyper-B[2]
I love bartender, also love the ability for it to show stuff if the icon changes for a certain time. Say weather app stuff, it can stay hidden, but if the weather changes might as well stay up there a minute or two then go away again.
Another app I love is Spirited Away, which will auto command-h an app after a certain period of inactivity. Can disable it as well but its an interesting way of keeping windows hidden.
Not a bad idea, though I don't know if the need outweighs the work of installing yet another background app...for starters, the menu bar really isn't that much "noise" (at least on the left side, I do agree that the background-app icons seem to proliferate on the right)...secondly, on an iMac screen, or even a 15-inch Retina, my eyes have more than enough real-estate to dwell on without even noticing the menu bar.
I feel you. I wish there was a better way. However, the application is currently using only 7MB or RAM and 0% CPU, according to the activity monitor (MBA ~ 2012). A small price to pay if reducing distractions is important to you.
I recently bought an iMac with Mavericks and the fullscreen applications work like wonders. They hide the menu bars and deck, letting you see them when hovering over the edges. It's my first Apple PC, so I don't know how it is with previous versions, but definitely worth a look if you're a bit of a productivity freak like me.
Full screen has a set of limitations for multiple monitors, either you're locked into one full screen app or the somewhat confusing world of separate workspaces for each display.
So Bartender just shows me my time tracker (important for client work), Fantastical (I could probably ditch this) and battery status; everything else is in the hidden Bartender draw until I need it. Just one hotkey away - I bind it to Hyper-B[2]
[1] http://www.macbartender.com/
[2] http://brettterpstra.com/2012/12/08/a-useful-caps-lock-key/