Hi, I know what you mean about being in bike uniform at work... we have staggered shifts here (people start at 530, 6, 630 , 7, 8, etc...)
so I can't really come and go without SOMEONE seeing me. But they all know I rode the bike in and they have gotten used to it just as they would if i was riding a motorcycle (They have a lot of stuff to put on and take off!!)
When you're only wearing this stuff when you are coming and going, they will associate it with your commute, not your daily outfit!

I have a 4 mile each way commute too, and yes, 4 miles IS enough to work you into a sweat if there's a hill. But lucky for me, MY hill is downhill to work and uphill HOME so I get home totally drenched..
but i get hill practice every day i commute!