[Divingduck]

Hello dmcd,
may be I can help you a bit to solve your needs.
To your first point: Two date fields. The second date field is used to see when a book was added into the library. When I update a book, i.e. if I made error corrections I update this field (different needs different solutions). If you do not want to use it you can hide it from the view with right click on the column header and select hide or you go to preferences-->look and feel-->book details or preferences-->add your own column and choose your favorite column view by activating or deactivating.
To your second point: Calibre put all available formats of a book in one folder. That’s how the Calibre library works - everything on one place in the library for one identical book. To have the right selection for the reader you have several methods to get these solve. One is to choose the right formats in the device-template. For seeing in your library only book formats you want, you can work with the tag-browser in the left and choose the formats you want to see. When you hold the Strg- key by selecting your choice you are able to select more then one criteria. Then save this as a filter. You can tell Calibre as well to choose that filter by starting the library. Take a look on the manual, there is a lot more of possibilities.
If you don't want to have some formats in the Calibre library, don't store them into the library or make a second library and leave them there. I do not prefer this way because you have to deal with two libraries but every one need to find the solution what works best for his needs. You can handle everything with a bit of creativity in one library.