cursor will not select icons when I double click

I have been having a new problem on my MacBook Pro. The cursor will not work properly. So far I have identified these problems: 1) the cursor will not select icons or respond to double clicks or operate my "hot corners,"2) In some websites it will start scrolling without reason, 3) It will temporarily resolve when I reboot but will shortly return to its prior behavior, 4) A Safe Start will solve the problem for a longer time but eventually this erratic behavior returns, 5) In Word the cursor sometimes disappears but not in all documents. Anyone have any ideas on what this is and how to resolve this trouble.