I agree that Humana is one of the worst offenders. The reps at Humana are the least trained members of their staff and reflect it in the advice they give. On their behalf, they are on a quota, so like to get you off the phone fast. To anyone who has a problem with insurance, go to your HR dept first. They are supposed to help you. Second, don't just post a complaint on-line to rant. File a complaint on-line with your state Insurance Commissioner. They do help people. The only way they will file against an insurance co is if they get complaints. Contact your state assemblyman. They will also help.
Never, never go out of network, except in a real emergency. Always go to your PCP and never pay up front.
As far as knowing if something is covered or not, remember everything is based on your policy and medical necessity and that is usually decided by the insurance company. If you use your PCP, though, you will not be responsible if he does something that is not covered. Part of his contract with Humana.