Hi, my girlfriend and I are planning on doing a trip down the East Coast of the US, mainly to see the big cities and get a taste of America (she's from France). We are leaving morning of July 4th, hopefully to see Independence Day celebrations in Portland, Maine with a couchsurfing host. After that, there are no dates but we plan on spending a maximum of 14 days. So far, our route looks something like this:

Montreal
Portland-
Boston-
New York-
Philly-
DC-
Pittsburgh-
Niagara Falls-
Toronto-
Ottawa-
Montreal

We are planning on doing some camping, some sleeping in the van, and some motelling, some couchsurfing.

As I said, our main goal is to see the big cities, since she's never been to the US and since I've only been to NY, having been born there.

I have a few questions...

We are planning on winging it, and mostly just have an idea of the places we want to go/see. Is that just stupid? Should we have a hard and fast itinerary?

A few years ago, I had a book that listed strange attractions to see while on a roadtrip, and I have no idea where it is anymore. It included things like world's biggest this-and-that, Museums of various ridiculous things, etc. and I was wondering if anyone knows where I can find something like that online. If not, how can we fill our trip with things to do between destinations?

I have more questions I think, but any input on the above would be immensely appreciated.