To be right about (doing) something

I can answer one of your questions. "Latest" means that more are expected "
"Have you seen the latest edition of "Hot Rod " magazine?"

Both sentences are correct. To be right/wrong about something means to be accurate or correct (or inaccurate or incorrect) (subjectively in the judgement of the speaker, or objectively) about a fact, e.g. John was right about Donald Trump; Mary was right about the car needing fuel.

To be right or wrong about doing something means, similarly, to be correct or incorrect about the advisability or wisdom of doing something, e.g. John was right about bringing an umbrella when we went walking; Mary was wrong about leaving school - now she has no qualifications.

It should be the Tories.

If you are talking about on the most recent election alone, use 'the last'; if your focus is on the fact that the election is the most recent of a (possibly closely spaced) series, use 'the latest'.

The sentence is correct.