"there was an observation outpost that spotted the Japanese planes coming in, reported it and was told 'dont worry about it, theyre ours'
p
plus keeping most of the pacific fleet in port and thus vulnerable isnt necessarily the best planning either."

That observation post was on Hawaii itself its warning would have made about 35 minutes difference, not enough time to matter given how long it would have taken to scramble and adequate number of interceptors or get the fleet moving since Pearl was not on alert and not considered a target. They really were expecting a fleet of B-17s. The radar being used at the time was considered experimental and couldn't tell the difference between less than a couple of dozen bombers and roughly 350 Japanese attack planes.

According the source I have, fleets around the world are in port 80-90% of the time. They wear out when they're out of port too much and battleships in particular were too expensive to keep moving too often or too long. The dispatches I saw showed the Japanese had intelligence indicating the battleships were in port and that the carriers were out. I've visited Pearl like a lot of tourists. It's easy to pick out which ships are in port from a good distance from the base without being noticed.