No, coron is 6-7hrs drive from astoria.
no, too far. you see many accommodations also at coron
No, Coron is on the northern part of the whole Palawan province, and can be accessed by flying from Manila to Busuanga Airport in Coron (about an hour ride). Astoria is in Puerto Princesa, about the middle part of the province and can be accessed by a different flight from Manila to Puerto Princesa airport. There is no flight between Coron and Puerto Princesa. Only brave souls would dare the ocean route from Coron to Puerto Princesa which may take 6-12 hours by motorized banca and quite dangerous. Not sure if buses ply the overland route but there should be though I can imagine 6 hours at the very least.
Get an answer from Astoria Palawan staff and past guests.