Imagine the following situation:
Four people go for promotion. One fails because he's late for the interview, and loses his job. One doesn't get the job because the interviewer is a snob and doesn't think much of his educational background, but he stays in the company and does well. One doesn't get the job because the interviewer is misogynist and the last gets the job and goes on to become CEO.
The first, begging in the streets outside the company, might say If I hadn't been late, I would have been the CEO.
The second, who is still there, might say If I had been to the right university, I would be CEO.
What would the woman say?
It could be used where we wish to emphasise the concept of finality, so not only for death- the basic underlying concept of the perfect is to show some form of completion. Rules are generally more models than rigid rules, and language is about generating meaning, so we can bend and adapt rules to suit our purpose. It wouldn't be wrong to say she would be 80, but it doesn't carry the same emotional impact IMO- would have been is more poignant..
I'd agree with that. To use the subjunctive construction ('If she were alive, she would be 80'), would be less effective here than the conditional sentence ('If she had lived she would have been 80'). Of course, in the original post, the first part of the sentence is understood, not expressed.
I am cautious about the bending of rules though. Certainly lets adapt rules if they don't serve the purpose. But I wouldn't be so keen if they clearly do serve! All seems to be in accordance with the rules here though, and we even have a stylistic choice, which is nice.
What if I talked about an event in the future that is less likely to happen since it will take place 2 years from the moment of speaking and there are things that might prevent it from happening, would it be correct to say "I would have been happy to graduate from University."?
What about this dialog from a series and my sentence about things that might prevent me from graduating from University?
"'I'd have been happy to graduate' = it's not going to happen!"
Check this situation out. Suppose I have the finals coming up but I haven't been studying hard in the semester. So I'm very unlikely to do realy good on the finals. I say to my friend who is a good student "You are going to ace the finals. I could've got an A but since I've been skiping lectures and haven't been studying hard it's not going to happen."
I would be talking about an event in the future, that's very unlikely to happen, rather than an event in the past?