How do you decide whether to trust a community fine-tune?

I'm researching how people choose and vet fine-tunes and merges from Hugging Face. I'm not selling anything. I just want to understand what people actually do.
1. Where do you find the models you try?
2. What do you check before you start using one (benchmarks, model card, reviews, your own test prompts)?
3. Has a fine-tune ever behaved worse than its base model? For example, odd refusals, lost reasoning, strange outputs, or things it should not say. What happened?
4. If a quick side-by-side check of a download against its base model existed, would you use it? What would it need to show?
Short answers are great, and stories are even better. Thanks!