So will i be able to make magic based on Elements (Earth, Fire etc) with the spell creation rules?
Yes. The spell creation rules results based, not based on the special effects, so you can easily craft the physical description to suit yourself. Take a look at the various Bolt spells (Infernal Bolt, Divine Bolt, Conjure Missiles, Mystic Bolt, Eldritch Fire, & Elemental Bolt). They are all based on the same basic Spell Base, with their descriptions customized to suit the School of Magic and what I saw as how those spells should work.
Basically, what you will want to do is to decide upon what powers/abilities are available to each element, and then create the spells accordingly. Similar to what I am doing for the Harn conversion (very, very, very slowly, but still...).