I was going to ask about this in a separate post but this seems like a good place...

Do you have problems with steering? Any sense that the stem is actually twisting? What happens when you lean the bike to throw your leg over?

I recently put a Wald basket on a beater to carry a 10lb box to UPS for shipping. The ride was terrifying. Here you have MUCH more load. Maybe I could tighten things up, change stems and move the basket down to a front rack. But I want to be convinced that it is a solvable problem without a frame-mounted basket (apparently it is).