Do not learn all those spells, some are useless, you should focus on getting ice arrow on jharkendar one very powerfull spell you kill Orcs in seconds, as for the blank runes you can get them from the master as you do quests for them.

In the monastary Gorax sells every chapter one or two of them.
You can get some rune stones as reward for completing these quests:
1 Snapper's claws (by Lutero)
2 Fernando's business (by Fernando)
3 I gotta get out of here (by Talbin)
4 Lurker Hunt (by Kerves)
5 The path of believers (by Pyrokar)
Ask Milten for stuff on chapter two and he will give you one blank rune,
In Xardas old tower in the valley of mines you can also find a rune stone.