Print ready files, canvas and pixels, sizes dont match

Ok following issue and i cant get my head around.

I have tested the demo-online version and compared to my site installation.

Things dont match at all. See the attached screenshots, with the same settings for the demo-shop and my site. 

i have set the canvases and print areas to the same sizes. but on my site the preview and also final ordered result is WAY better and sharper. (i dont have the pro compared to the demoshop!). Still the demoshop looks more aweful.

Aside from that even the result for the print ready files - base - are way to blurred due to somehow an internal rescaling.

while downloading the individual elements, these are crystal clear and sharp.

So in first:

how can one get a decent canvas and maintain a decent work/printarea ? basically a 23cm wide and 9cm height print area will always result in a tiny workspace for the customer.

how does this work together? how can i have a decent sized editor/workspace and the printable area also in a decent size  and still the printresult in an acceptable resolution? 23x9cm with 300dpi and sharp elements? do i really need to download each element individually and rebuild the stuff in illustrator or photoshop?

When i compare it with the demoshop which has the pro features and export enabled, using the same settings i have for my site - the result is ABSOLUTY bad - therefore not worth to buy the pro.....