Welcome, Schleiffer!
Your answers are all correct.
If I want to invade lets say Portugal from Spain with ground forces and I have a battleship in sea zone 91 whithout any transport for an amphibious assault, can I bombard with my battleship?
And another silly question: In a ground assault with tactical bombers and other land units do the tactical bombers fire once and land or can they fight for all the rounds we fight?
No
They can fight all rounds
Thank you Calvin