Hello all, I'm "new" at the forum because i usually don't ask, i read and search. Anyway, I'm still learning a lot about tools and how/when to use them - there're a LOT of them!
Some questions keep going on my mind and i haven't found a post that discuss exactly what I'm looking for and, maybe, it will help others with the same questions:

About Aircrack on WPA:
I have read a lot of way cracking wireless and i found two ways for WPA/WPA2: Bruteforce and Evil twin.
1-Is there any other effective way of cracking WPA?
2-How effective is bruteforcing with a Dictionary attack? I know there are programs to reduce and "fit" to a specif model your wordlist, but i think it is still so inefficient. For example, my wireless in a 8 numbers passaword length and i tried bruteforcing. Reducing my dictionary to a only 8 digits numbers would take, in average, 6 days to crack my password. Is this the idea? To let the computer running for days until it finds the correct match? I know i could batch the wordlist, etc, but it still ends at the leave-the-computer idea.

About MetaSploit:
1-All videos I've seen they can only exploit the computer when it has the AV down. So, I thought, at real, how effective is this exploit?
2-Is the bypass a A.V. and a Firewall the most hard difficulty when hacking into computers?
3-A lot of videos use some kind of social engineering to get the archive to the victims computer or it makes the person tell what he want. So what i conclude of this is that it is almost impossible to hack into someone's computer if you don't get any "help" from the victim. Am i right?

The Objective of this thread is to instinctive the discussion, the reflection about how the entire hacking process work.
Hope to get some useful answers and interesting points of view.

It is all for now,