just a little more on #4
There are two ways to increase magic paths. Through items which you can forge(see Construction 4 item Thistle Mace that takes 2 nature magic and 10 nature gems to forge,
this is a list of magic items, they will be listed there, or after looking for it, a list of all magic boosting items is
here. The extra level(s) in the path last only as long as the mage is wearing the item.
The other is Empowerment. Youll find it in the same list as search for magic sites. You use a number of magic gems to boost your mages magic path(nature for nature magic, earth for earth, etc etc). This boost is permanent but expensive.
If its just searching for magic sites, pay attention to Mork, there are no magic sites above level 4 in a magic path.
/edited to clean up a bit and add a new link.