1.) Yes, you can add multiple URL/Text...in textbox. JDownloader does parse the text for links, you can just copy/paste and let JDownloader find the links. Please know that only single links will be *deep decrypted*(finding links in html) by default. there is an icon besides the add button to change to deep decryption and then you can also add mass links
1.1.) You can also make use of Linkcrawler rules and teach JDownloader how to process your links. That way you can simply copy them to clipboard and JDownloader will process them and find your content. Try to use board search and ask if you need help with it
2.) Yes, you can either manually specify a package name in AddLinks dialog or make use of Settings-Packagizer and create rules that auto parse/set package names and other properties
2.1) In Linkcrawler Rules you can also tell JDownloader what to use for package names
3.) should be solved once you've set package names but see below
4.) should be possible but see below
We can help best(even with Linkcrawler rules) when you can provide example links(and logins if required) to
support@jdownloader.org