So then I have to re-key my purchased scripts and that process is so aggravating.
If your scripts are via AEscripts.com, you can get their AEscripts and AEplugins manager app. Check it out here. It helps you with downloading, licensing, and registering the stuff you've gotten from them. It works great for almost everything they sell.
My question is has anyone had similar behavior with the work spaces and if so have you found a solution?
There have been a number of people with workspace-related crashes. You shouldn't have to trash all of your preferences, you have to go into your folder structure and remove the files out of the ModifiedWorkspaces folder. Then relaunch AE and it usually works for most people. Some people with workspace-related issues have the MIDAS extension from Mt. Mograph and uninstalling it made AE work too.
And has anyone had problem with playing back .MTS files and have it crash repeatedly? If so how have you fixed it? (The .MTS files are like 4k with some color correction effects, Key Light and a couple Layer Style effects too.)
MTS files are often MPEG-2 or other MPEG-related codecs. There have been a few people having issues with long-GOP codecs and Keylight. That may be the problem. Sounds frustrating though. Try transcoding to something like Cineform or DNxHD.
Also, what exact version of AE are you using? I know you said CC 2017, but is it version 14.0.x, 14.1.x, or 14.2.x?
After reading Szalam's response and trying those things, were you able to overcome your crashing issue? Please let us know.