Anyone knows which of the various addons, like lora embeddings will overide the prompt meaning even if not selected on purpose?

For the embeddings, if one uses the name of the embedding as a word in the prompt, that embedding will be applied.

What if the embedding has other words that can trigger it, words that we don't know about? Lets say you have an embedding to apply a certain person. what if the author also included by mistake the word "car" but we don't know about it. Is this possible for the embedding?

The loras stay disabled till we use the <lor:> tag or they trigger just by using the words?

I want to be sure that downloading all these files will not corrupt the outputs with unwanted weights

The trigger word for TI embeddings is always the file name, so you can easily change it if needed. Unless you have one named like "car.pt" in your embeddings folder it shouldn't be an issue.

Also, yes loras need to be enabled with the tag for their trigger word to have an effect.