I have a feeling that my computer is infected wih something nasty can anyone take a look?

For a moment, let's go back to all of these images you posted. They're all normal items. Forget them.

Running EtreCheck in Safe Mode is useless. The OS only allows specific fonts, drivers and functions to load. Any malware you may have won't show up since it can't load.

Do all of the following from a normal startup. Not Safe Mode.

To repeat from above, run MalwareBytes for Mac first. If it finds anything, let it remove all malware/adware it detects. You can then uninstall the app. The uninstall option is in its menu items when the app is running.

Then as Grant noted, you must give EtreCheck full disk access, or the report will be essentially useless. Download the Pro version (if you haven't already) from the EtreCheck web site. It can do more than the App Store version.

Run EtreCheck and turn on full disk access in its interface, as Grant mentioned.

Open the System Preference and click on the Security & Privacy icon. Add EtreCheck to Full Disk Access.

Now run EtreCheck and post those results.

Apologies on the EtreCheck report. It's pretty unusual to have such a short, or empty listings for the Launch Agents and Daemons. I went right past them trying to read the report from an iPad.

What you have is almost the same as an out-of-the-box Mac. They only difference in running processes are a few Safari plugins.

As far as any lag time you may be experiencing, you only have 8 GB of RAM installed. That isn't really enough for Mojave. The proof of that is your Mac has almost nothing running but the OS itself and the Mac is still using swap space on the drive. Which in itself is a bit odd because is shows a bit over 5 GB of available RAM, and yet, is still using 96 MB of swap data. An odd anomaly, but not evidence of anything suspicious.

Well often times my background will change on its own (I'm not talking about the light and dark feature)

Check your screen desktop and saver settings to see if it's set to change the desktop every x number of minutes.

Fonts will sometimes be oddly different, close to what they should be but enough that it is noticeable.

Could just be corrupt font cache data. Or, third party fonts you've added that are conflicting with other fonts. But this again isn't evidence of anything.

Strange highlighting around text fields, as if it is on a different "layer" than the background. ( I guess you could say that it it could be "masking" the legitimate text field.

Sounds like you accidentally turned on Text to Speech or VoiceOver. Check in the System Preferences under Accessibility to see if either is on.

Here is another thing that I'm sure is normal but I'm not sure what it means (What is with the Device tree path???)

You're trying very hard to find a problem without even knowing what you're looking at. It's normal. Ignore.

Or why I can only ever use 251G of my 256G HD ... I defiantly remember when I started my Mac for the first time that it was more than 251 but maybe I'm wrong.

No one in the world gets as much usable space out of a storage device as its blank size. There's formatting and partition data that takes up some of that space. The drive table entries. The hidden EFI partition that is on every single physical drive. You are once again trying to find a problem that doesn't exist based only on not knowing what it is you're looking at.

Bottom line. Stop wasting your time looking for ghosts.

You left everything out of the report that would be useful. Or, you didn't give the app system access.

Download and run MalwareBytes for Mac. It may not find everything, but it'll be a good start.

https://www.malwarebytes.com/mac/

It's free to use.

Diagnostics Information (past 7 days):

Directory /Library/Logs/DiagnosticReports is not accessible.

Enable Full Drive Access to see more information.

Etrecheck > Preferences > [√] enable full drive access

Those screen shots show the same files that are on every Mac. If you are simply looking for strange-looking files, I can suggest some other locations. But if you have specific problems that you would like to ask about, I suggest you start there.

What exactly are the “glitches” you referred to? What exactly is not working right?

I can only assume you still have not given EtreCheck full disk access. The report skips everything we would need to look at.