To get around having to spend the feat on Skill Focus, consider some levels in the Master Specialist prestige class from Complete Mage. You only need spell focus in your specialist school to get in at level 4 (with the ability to cast 2nd level arcane spells), and if you stick with it from levels 4 - 7 you get Skill Focus (Spellcraft), Greater Spell Focus (your specialist school), an extra spell known, and Minor School Esoterica.
MSE is an ability which varies based on your specialist school. Diviners, for example, get to have their concentration-only spells stay in effect after concentration ceases for a number of extra rounds. Personally, I favor Illusion (+2 DC on any illusion spell that has "Will disbelief" in its save entry) and Conjuration (+level added to hp of all summoned creatures).
Anyways, master specialist could give you some useful extras while you're making your way up towards Loremaster's prerequisites.