Will be flying into Shannon a few days prior to our tour which starts in Ennis. Any suggestions? Will we need to rent a car for 3 days or should we taxi to Galway and day-tour from there? Can we rent bikes while in Galway - is it close to a national park?
I think it would be an expensive taxi ride. You could rent a car and that way you could explore the countryside. There are day tours available from Galway
Have you looked at Google Maps? Would show you it would be one extremely costly cab ride.
My suggestion to you is to buy an Ireland guide book
And read up on Galway.
There are quick and simple buses between Shannon and Galway. Use one of those.
We based in Ennis prior to our tour start and took the bus from Shannon airport to Ennis, which was very easy. We also took the bus from Ennis to Galway for a day tour and that was easy, although maybe we could have done a train. Galway would give you a central location for touring the area and there were some guided tours that wouldn't require you renting a car.