Hi,
I think all your issues come from the fact your data was created with the DNN localization on, hence your product data is corrupt, importing it may reintroduce the error!
I suggest you create a fresh DNN install and load up a fresh store without importing the products, get that working with a couple of products and then back it up. Only then try importing your product data, and cross your fingers hoping it doesn't crash! :-)
I think all your issues come from the fact your data was created with the DNN localization on, hence your product data is corrupt, importing it may reintroduce the error!
I suggest you create a fresh DNN install and load up a fresh store without importing the products, get that working with a couple of products and then back it up. Only then try importing your product data, and cross your fingers hoping it doesn't crash! :-)