How about Assen





A track that sprung to my mind was Qatar seems like a lovley track

Assen's is way to small and tight. F1 could never ever make it there.

I like Qatar, but Bahrain is already there and they are both somewhat similar.

is it possible to put F1 cars (with heavy restrictions) for the Nordshleife or are the barriers and run offs just completely inadequate?

It's not that the barriers and run-off areas are inadequate, but tat it's too difficult to maintain the levels of safety. This was one of the leading arguments for shortening Hockenheim: there were some very isolated parts - namely the Ostkurve - that were simply too difficult to access in the event of a really bad accident. The Nordshleife has the same problem, but worse: some sections are very isolated.

And if you placed heavy restrictions on the cars, it wouldn't be Formula One.

You mean that patch of forest, where they ripped up the track and planted trees.