Using training data without explicit permission is (probably) considered to be fair use in the United States. There are some currently active court cases relating to this exact issue here in the U.S., namely Getty Images (US), Inc. v. Stability AI, Inc. The case is still far from a decision, but it will likely be directly responsible for setting a precedent on this matter. There are a few other cases happening in other parts of the world, and depending on where you are specifically, different laws or regulations may already be in place that clarify this specific area of law. I believe there is another case against Stability AI in the UK, and I've heard that the EU was considering adding or has added an opt-out portion of the law; I'm not sure.

Yeah, and DDR4 DIMMs are fairly inexpensive as compared to upgrading a GPU for more VRAM.

Does that increase inference time?

Yep; it used to access chat.openai.com and used Puppeteer (headless Chrome) to semi-automatically traverse the login. They're claiming now that they have some sort of more direct access (not GPT-3 API) and that method is obsolete, so I'm not sure what it's doing now.

There's a NPM package that provides an unofficial API for ChatGPT, but you have to jump through all of the hoops to get signed in before it can snag the necessary credentials.

You could probably do this with SD's textual inversion and EBSynth. Not in real-time, but it's one way to go about things if you're making a video.