Boy oh boy. That's some serious corrosion. I'd back the suggestions that you get someone to take a look and remedy the rusting. I've had steel frames for some time as have some of my friends. Well cared for and they should not corrode so quickly. As I say I've ridden a 40 year old steel frame which I've owned for 25 years and there's little corrosion.
Thanks for your suggestions of an intro. This is my first evah forum of any sort - it's good to know background. And I do love riding my Surly. Lovely bike.