Sims 3 Keeps Crashing, Repeatedly

@TheRaddestCrow  Let's start with the easy answers.  What I meant by a classic mod is just one that goes in Mods > Packages.  There are other types of mods that go elsewhere, for example HQ mods are really edits to the graphicsrules file in the game's program files, with the intent to force higher-quality graphics settings than the game would allow under normal circumstances.  If you haven't messed with the program files, you're fine.

The Smooth Patch would be an example of a nonstandard mod, as its main component goes in the Bin folder within the program files, not in Packages.  I don't think it would help here.

I would recommend adding NRaas ErrorTrap as well for the overall health of your save, plus MasterController for its set of convenient commands.

Limiting fps can be done on any system.  I'm not sure whether it would help with your crashing issues, but it's simple enough to try.  Download RivaTuner Statistics Server (from guru3d.com; it's free), install it, add TS3.exe (without the W) to the list, set the fps cap to 60, and restart your computer.  Open Revo again, since it needs to be open in order to work, and see whether it helps.  You can set it to start with Windows if you prefer.  It won't have any effect on any program for which you don't set an explicit limit.

However, I think the issue might be the Pets expansion.  It's the most demanding pack by a significant margin, and it causes crashing on lower-end systems even when the player does everything else right.  If you don't want to stop playing with pets overall, try avoiding horses and long-haired dogs, not only in your active household but overall in the world.  For the dogs at least, you can take them into Create a Pet and change their coats.  To get rid of the wild horses in the world, you'll need NRaas Register.

Finally, an access violation is when an application tries to access memory in a manner that is not allowed.  This can be attempting to read, write, or execute at a memory address that doesn't support that function, or at a protected address the application isn't allowed to access, or something like a null pointer where the attempt itself isn't in a valid format.  Windows detects the problem and kills the application.

The point here is not only that there are many types of access violations but that they can happen for an even larger number of reasons.  So knowing that an access violation has happened isn't particularly helpful unless you're a developer testing or debugging the application.