[GeoffR]

Originally Posted by miztiik

Is the kobo Aura jailbreakable? How easy or difficult is it?

The Aura (and other Kobo e-ink readers) are not locked, so jailbreaking is not applicable.

Edit: Unlike other models, the Aura and early Touch models don't have their firmware on a replaceable internal SD card, so there are fewer options for recovering from a hack that goes wrong than there are with other models.

(I don't know anything about sideloading dictionaries sorry, other than it is possible.)

Are the annotations or making notes, takes you away from the page you are reading?

Making notes is done without leaving the page you are reading, but the keyboard and notepad occupy the whole screen while you are typing in the note.

Also had there been a fix for "GoTo Page" request?

There is no option to type in the page number to jump to within a book (there is for navigating the library lists).

Edit: There are now a lot of different page numbering options: page number, percentage read, time remaining; each per chapter or whole book; or no page numbers at all in full-screen mode. The slider still works to navigate to a particular page whichever option is chosen.

Is it possible to have a custom slideshow screensaver? (I used to have this on a old Sony)

Sort of. There is a shop demo mode which shows a slideshow while the device is in sleep mode, and you can change the stock images to whatever you want. But it is probably not very useful, at least I haven't heard of anyone actually using it.

Edit: Now I remember, it is not useful because the touchscreen remains active during the slideshow, so it is not really a sleep mode, it would drain the battery faster than normal reading.

Finally, i have read some posts refer to "Koreader" what is that?

It is one of a number of third-party readers and that can be installed (on Kobo and other devices.)