Uninstall AVG by following the developer's instructions as anti-virus apps are not needed on a Mac (MalwareBytes is the exception because it can actually detect and remove malware from a Mac without causing other issues -- plus you can configure it not to run the real-time scanner all the time). I also recommend uninstalling the Sensei app. While it includes some monitoring features it also includes cleaning abilities which is not needed on a Mac again because it usually causes more problems than it solve plus it impacts system performance. I also don't think the Intego Content Barrier is necessary either (I don't know anything about how it interacts with a Mac, but it really should not be necessary since macOS provides a lot of built-in security without requiring any third party apps).
FYI, I won't even install AVG on Windows anymore because AVG is absolutely terrible these days (I used to use AVG on Windows 20 years ago). In fact I won't install any third party anti-virus apps on Windows anymore because they are all terrible these days (I just use the Windows built-in anti-virus).
I'm not familiar with those Safari extensions. I would definitely be careful using any browser extensions especially Chinese ones. So many browser extensions are shown to be buggy if not outright riddled with malware or they invade your privacy.
I'm also not familiar with "starstechnologies", but I'm not familiar with a lot of legitimate macOS app developers either so this may be fine -- I just don't know what it is. I believe I've seen the "imobie" tools in other reports where no one commented on any problems with this tool (again I know nothing about it).
As for a swelling battery do you detect any deformation in the case where the Bottom Case may be starting to separate from the rest of the laptop? Does the laptop sit nice & flat on a flat tabletop? Do you notice the Trackpad rising up above the level of the palmrest? Does the display close properly? The only other way to detect a swelling battery is to have an Apple technician open the laptop and actually view the battery to see if there is any swelling that hasn't yet caused the laptop to deform.
The only way to see if the Trackpad is the issue instead of a software issue or hacker is to boot from an external macOS drive or Internet Recovery Mode to see if the pointer moves on its own. However, like I said some trackpad issues are intermittent and can take time to occur again and it sometimes requires actively using the trackpad to help trigger the failure which is hard to do from Internet Recovery Mode so an external macOS boot drive is best for testing purposes. You can install macOS to an external USB drive by booting into Internet Recovery Mode or by using a bootable macOS USB installer.
Of course you can always restore from a backup made before you encountered this issue in case it is caused by software (make sure to perform a clean install of macOS by first erasing the whole physical drive before installing macOS and restoring from backup).
Perhaps another more experienced contributor will chime in to offer some advise as well.
