1) Is it possible to switch to an individual plan without the owner's consent? No, in order for the Transfer of Service (equivalent terminology for Assumption of Liability) to take place, the account owner needs to "release" the line to you. The account owner is responsible for that line, legally, and so any changes need to go through the account owner, or an account manager. If you are an account manager, you MAY be able to do this on your own. 2) Will either account be billed a fee? No, the responsibility and ownership of the line moves from one account to another. There is no "fee" to do a transfer of service.
3) Do I have to wait on my phone's contract to end before I can switch for an individual plan? If the phone is in a contract, then no. If the phone is just on a 2 year payment plan, it's not on a "contract" per se, and the balance due on the phone needs to be paid before the line can be transferred.