I don't think that an ancient navy was capable of projecting effective power to such distances. All naval campaigns of antiquity were on much shorter distances and on routes with better supply possibilities.
Even if they did not met opposition on the way it would have been a long difficult journey and they could not do much to help the city against the land assault of Alexander perfect war machine.
Q1: it was a island city, always a very difficult target
Q2: Alexander was a great general with the most powerfull army of the time. I think the siege shows the military qualities of them, but, maybe, a low diplomatic skill. Wasting time and men in front of Tyre let Darius time to rebuild his shattered, but not destroyed, army.