OK, I'm just putting in my 2 cents on the usage of "will' and "would". I guess this is more on the surface but may be useful in clearing some of your doubts.
I think in some situations when you're more sure of the consequences, "will" can be used instead of "would".
Sentence 3 is a good example of using "will", not just because of a high possibility/certainty, but also the sentence structure "if ... (verb in present tense), ... (will + verb)..." always suggests conditions where action A will likely lead to result B.
If "would" is used in similar structure, it will convey an imaginary sense, which means things are just imagination and may not happen in real life. For example:
If I were born 10 years later, I would still be studying hard. (which is not likely to happen as we can't "be born 10 years later")
Hope it helps! Meanwhile, let's wait for others' contribution to this question! ;)