There is a Respec Potion in the game, however it is not enabled by default. In order to enable it, you can download the respec mod found here: http://www.torchlightinsider.com/forums/showthread.php?t=270
Then the shop vendor will sell them for 3000 gold.
As for the spells, if you choose to keep the spells equipped, yes, your scrolls are obsolete. If you choose to increase your number of more combat-ready spells to 4, then you may need those scrolls again ;)