RE: There are scuff marks on the wall that I have to fix.
Offer to fix them for her. That's what I do. I know I mark up the wall, and I also know that we have touch-up paint in one of the storage areas that matches the wall color. Every couple of months, I bring a small brush and cover my bike marks.
It sucks that you're related to this hag. I don't know what all your options are, but I suggest taking a bit of a stealth/guerilla tack, as long as it won't get you fired. In order to kind of conceal the fact that I bike to work and have a lot of extra stuff (clothes, washing supplies, deoderant, etc.), I grabbed an extra filing cabinet. Most of it is full of bike/clothing stuff, not paper. I also set up a "covert" laundry line under my desk (I have a cubicle with a counter-like desk). I hang my towel, sweaty jersey/socks, and washcloth from this, and turn on my little fan (also under my desk) to dry the stuff out before it gets a chance to stink.
Here's a guy who stores his bike under his desk (last picture):
http://www.bikecommuters.com/2007/06...d-gear-friday/
Let us know if you come up with other alternatives. It's fun beating the system.
Fight the power....