Would it make sense to try and master just one of these instead of practice them both?

Hook generally is a reliable disarm. Disarm with axe vs. most weapons is kinda unreliable. Weaponbreaker is unreliable but has the obvious benefit of breaking the weapon, and can be used while blind.

Both are good, some weapons can't be hooked, some can't be broke. They both have their place.

Those that cant be hooked are those with the no_remove bit? or are there others that cant be hooked as well except for daggers?

It's been a long time since I had an axe spec, but I think that is correct, just daggers and yeah, norem weaps you can try to break instead of hook and when they're unbreakable, then you try to hook.