With amphibs all you need are a few well located refuelling stations equipped with some basic maintenance provisions,while the main bases will house weapons and other required eqpt.
nice thoughts but like the using highways for fighter aircraft not that practical.
Also where would the amphibious aircraft be?? if they were in the same vicinity and some would have tobe - the tsunami would have clobbered them. (ignore advanced warning - because in that case so can the land based aircraft take off)
and real aid eventually needs large ships
BTW I have no disagreement with you larger number of helo carriers\LPD etc with ability to carry harriers.
But do note that once we run out of Harriers - we have limited choices in the future.