Whenever I touch my phone even with just one finger the screen keeps shifting around, also the fact that the keyboard jitters most of the the time when I try to write a word my keyboard would pick more than one character of letter. It might be auto correct or replace text i dont really know.
When was the last time u restarted ur phone? Cause u got a lot of ram u need to clear and a restart solves most common issues. Phone jitters are one issue that can be fixed with a restart and update of all apps and system software. A system update can be done by going to settings and clicking on software update. Inside software update; click download and install to receive latest security patches.