In Calibre You can select several books at once, and hit convert. It is an old feature, described on the official blog:
Bulk convert: Calibre allows you to convert books in bulk. You can
select a set of books, all of which may or may not be in the same
format, and convert them all in bulk to a different format. So say you
have a kindle and you have ...
By deleting an ebook I assume that it is a matter of a book that you have purchased and finished reading. In this case if you delete your book from the online library all Kindle synced devices that had the book will also delete it.
In case you are talking about a book that you have published, and then unpublished for editing, the previous version of the ...
I think I see the problem (or one problem at least).
I have a massive set of collections on the kindle app for android. (Like 50 collections holding 2000 or more ebooks).
But when I install the Kindle for PC app for my Windows desktop, it does not let me import the organized collections from the Kindle app for android. When I use the Kindle for PC app, ...
Usually a .mobi file actually includes a couple copies of the book in different formats. Is the .mobi file much larger (like, multiple times) than the epub file? This is the giveaway. The KindleStrip plugin (http://www.mobileread.com/forums/showthread.php?t=96903) might help you remove that excess content to bring the file down to a manageable size.
After adding your new PC to your Amazon account as a Kindle device, and after downloading Kindle software onto your new PC, then open the Kindle program, and choose Collections, click the plus sign, and choose Import Collections.
New (April 2014) Solution:
Go to Amazon Cloud Drive (https://www.amazon.com/clouddrive/).
Select documents (one-at-a-time only) and click Download.
Old Solution that can work without Internet Access:
Deliver the documents/books to your iPhone or iPad Kindle.
Download & install an app such as iFunBox Classic (free). This app allows you to ...
I have tried the following:
Go to "Manage Your Content and Devices"
Delete a document (NB: not a book bought from the Kindle store)
On my Kindle (Paperwhite) go to "Sync and check for items"
The document still shows on the device.