That's why I love Nova Prime it will prevent that , they have a setting for locking the desktop so you won't accidentally hit or move the apps around.....
You can use a case. There is no official touch screen sensitivity reduction option but there are some touch screen sensitivity apps in the play store. I haven't used any of them though.
It must be the way I hold it but when I type I almost always hit the num button when trying to press the t. This is on the google keyboard. Its been quite an issue for me since day 1