There's always a risk but considering currently there's no incentive for ppl to invest their time and sanity, I think you're fine.

Unless you do stupid things. No one is liable if you do stupid things :)

Google collects absolutely everything possible and tries to connect the dots. They have everything posted publicly in their archives along with everything you've ever given them in private, and anything others have given them. If you've ever used Android with Google services, they have had access to everything about you. For Google, nothing is mundane; nothing goes under their radar.

That alone won't, but if someone irl suspects they know who you are your silhouette can be used to verify/confirm.

It depends. Is your head perfectly spherical?

If you did it with someone else’s photo and THEY said it was doxxing, I think I’d be inclined to side with them. Since it’s your own photo I reckon you get to decide whether or not it’s doxxing.

I’d hesitate to do it myself, but I send a lot of lemmy posts to my friends, who are very intentionally not all equally apprised of my interests/identity lmao

I wouldn't, just to be on the safe side.

Eeh, i dont think anybody will be able to find you based on that. I myself have as pfp a drawing a friend of mine made, and its been fine

Well it's tracing so presumably the outline would be very similar to the real outline and you'd be recognisable.

No

Why would that be the case?

If even doing the traditional equivalent was as bad as the basis of this question implies it may be, then one could say I may have kinda taken the misstep.