Start-up screen off-centre

Regarding the slowness of your Mac download and run Etrecheck.  Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:

Also click and read the About info to further permit full disk access.

Copy the report

and use the Additional Text button to include the report in your reply.

We can examine the report and see if we can determine the cause of the problem.

Hi chiefsub63,

We definitely want you to be able to enjoy your Mac and we're happy to help.

Does the issue occur while in safe mode? If you are not familiar with the safe mode steps, you can follow the steps here: How to use safe mode on your Mac to get it done. Once in safe mode, you'd want to use the Mac as you normally would to see if the issue occurs again. You can tell when the Mac is in safe mode because on the desktop it will show the words Safe Boot in the top right-hand corner of the screen. 

If you already have another user account set up, then you can use that one or create a new one to test in using the steps here: Set up users, guests, and groups on Mac

Best regards

The report looks OK. None of the usual suspects. Glad you narrowed it down to the tablet software.