In english we often use "would" to directly make the sentence hypothetical, but how would you do this in Japanese?
You would make a good actor. 役者になったら、上手と思う (If you were to become an actor, you would be good at it)
This sort of thing would be popular in Canada. カナダにあったら、こんな奴は人気だ (If this was in Canada, it is popular)
I can't get the same meaning from Japanese...
For the conclusion clause: だろう／でしょう adds the sense of assumption. I find these are closer to English 'will' (でしょう is polite). These can be used in the conclusion clause but not a grammar requirement. For the uncertainty of 'would', we say かもしれない.
For the premise clause: When we especially have a need to say it's hypothesis contradicts an actual fact, we do that by adding some expressions. For example,
The above sentence means that it's very rare case but still possible. Here, なる for the future. Both あった and ある works for the future in the premise clause.
This is for the past. So, it's something about no longer possible.
Cf: In Japanese, we use the helping verb た not only to express the past but also the sense of completion in any tense. Not like English has the past tense form and the perfect form separately.