1. <Home>, <End>, <Up>, <Down> keys simply don't work.
2. So, we can not quickly distinguish range of symbols to delete, for example.
3. If we marked some range of symbols nevertheless ( by using <Shift>+<Left> many-many times ) and want to delete them all, after <Delete> only one first symbol will be deleted and it is really confusing.

I tend that these symptomes are bugs, not the behavior which anybody want to have.