First, let rewrite the first sentence of your question to comply to the recommended practice required for the answer to your question.
"I was talking to a friend and I had to make a hypothetical statement about an activity that would be completed in the future."
Past hypothesis, present accomplishment
I could have been a singer and I should have a million dollars now.
I might have been a singer and I might have a million dollars now.
Were I to have been a singer, I would have a million dollars now.
Present hypothesis, future accomplishment
I could be a pilot now and then in twenty years' I will have flown a million miles.
I should be pilot now and then in twenty years' I shall have flown a million miles.
It is impossible for me to be a pilot due to my eye sight. Were I to be a pilot now, in twenty years' I would have flown a million miles.
Future hypothesis is similar to present hypothesis
He is deeply considering that if he continues college now (rather than next year), he will complete college in 2013.
Optative resulting in speculative outcome
He has quite a number of choices. He could continue college now, and then he would complete college in 2013.
Speculative with possible outcome
Despite his decision not to, if he continued college now, he will have completed college in 2013.
Unlikelyhood with impossible outcome
It is unfortunate that he died, but if he were to continue college now, he would have completed college in 2013.
Additions, in defence, due to comments
Concerning the comment that the last example should be "if he had continued" - it would not denote a past impossible situation, because it is a speculative rather than an impossibility subjunctive.
The impossibility subjunctive requires the narrator's view to be temporally displaced into the future of the event.
Therefore, if the narrative is the present, its impossibility subjunctive would have to use the past or past-perfect tense.
Even if the event is in future with respect to the current narrative, the impossibility subjunctive requires the temporal displacement of the narrator to be placed after that future event. (BTW, temporal does not mean "temporary", but "time-based".)
Need to differentiate between a future expectation, a future subjunctive, and a present subjunctive.
Future expected acquisition of state due to completion of event:
(He is graduating today.) Next year, he will have been a mathematician for a year.
Future subjunctive acquisition of state requiring temporal displacement of tenses:
(Were he to have continued school, he would graduate today.) Next year, he would have been a mathematician for a year.
Present subjunctive event (without acquiring state) requires temporal displacement of tenses:
(Were he to have continued school, he would graduate today.) Today, he would be a mathematician.
The classic example of Present Impossibility Subjunctive is
If I were a bird, I would sing all day.
I he were alive now he would continue college. If he were to continue college, he would graduate in 2013.
Past Speculative Subjunctive
He is a rather intelligent fellow and had a high chance of being a mathematician. He could have been a mathematician rather than a carpenter.
Future impossibility due to past speculative condition
If he had continued college, he would have graduated last year. If he had continued college, he would have been a mathematician for a year, next year.
Using or not using past-perfect tense for a future subjunctive is illustrated:
Future subjunctive to narrate acquisition of state due to completion of event:
Were he to pursue his Masters', he would have completed it next year.
Future subjunctive to narrate completing of an event without acquisition of a state:
Were he to pursue his Masters', he would be completing next year.
He has started reading for his Masters'. If all goes well, he would complete it next year.
Future expected possibility due to past condition
Fortunately he had continued college. Next year, he will have been a mathematician for a year.
If you disagree with the aspect of temporal displacement of the narrative of a subjunctive, you need to tell me how to differentiate between narrating
- the completion of a future subjunctive event ("subjunctively" acquired a state).
- the completing of a future subjunctive event ("subjunctively" acquiring a state).
- a future subjunctive event (no state acquisition being narrated).
- the future completion of an expected event (expected acquisition of state).
Whatever you interpret from grammar books, even if you are a respected grammarian, first find out if your structure is able to make such a differentiation. If you can/could, let me know.
You cannot say that we have to use the future subjunctive in place of a perfected future subjunctive.
You cannot say that we have to restrict ourselves from being able to narrate a perfected future of a subjunctive. You cannot say that it is not possible to narrate a perfected future of a subjunctive.
You also cannot say that we have to restrict ourselves from being able to differentiate between future subjunctive, future perfected subjunctive and a future expectation.