I have had a Kobo Aura for a couple of weeks and I am very happy with it. I have been reading the Kobo threads for a couple of weeks and I haven't noticed that stuck pixels is a particular issue with the Kobo Aura. I know that stuck pixels were an issue in the early days of LCD screens but I understand it is extremely uncommon now.
As for the "cracked" screen, that happened to one of my Sony ereaders. I took it back to the shop and they told me it is not necessarily the result of an impact. It results from localized pressure on the screen (that is, if the reader was on a table and someone leaned on it). It could happen to any reader.
I can understand why you might have gone off Kobo readers but your unfortunate problems are not specific to any particular brand of ereader.