Play Games - Interact - Have Fun!
I'd be grateful if anyone could answer my query below.
This may be obvious to most. If both players have wizards the rules suggest the player with the initiative can attempt to cast a spell (which if successfull their opponent can try to dispell). Then their opponent can try to cast a spell. Is this the end of the magic phase, or can each player continue to cast spells until they have exhausted their hand or do not wish to cast a spell?
You have it right.
Each side's wizard casts one spell (in order of initiative) and if successful, the enemy player may attempt to dispel it.
That being said, a cool optional rule would be to allow players to "upgrade" the most powerful wizards (200pt) to allow a 2nd spell casting attempt each turn in lieu of moving a ship or squadron. This attempt would be made at -1 due to the draining of the wizard's powers from the earlier spell at the beginning of the turn.