The first has to do with the history substitution, when using the up and down arrows to retrieve history events sometimes the event is added to the command line on top of the previous command causing gobbley gook to appear on the command line. For instance, if I entered the three commands recently of pwd, ls, less file then use the arrorws I might see the command line list less fiwd The wd gets appended to the command line and the backspace key cannot always erase the line. Hope I am explaning this right. This happens some of the time but not all of the time but enought to make history substitution problematic.
The other thing I noticed which may be related is if I less, more a large file the file contents display 1 line beyond the command line making entering more commands a problem. It appears the shell behavior is the issue but I have no idea where to start, any ideas?