I'll try wide tires. If the worst comes to the worst I could construct a shorter rack. I haven't taken it off yet to see how it rides. I find (eg) on a busy rode I want to change lanes (I don't have a mirror yet) and while I look back I sway off course (honk). I was hoping this would be a nice little runabout with a rack.

I'm riding a small but I only weigh 60kg and I notice if I lean back the balance helps (like skiing).

There must be some significant leverage factors with a long rack (if I remember - a "moment").
G