"No. Again, bitcoins are not "backed" by anything. There is nothing the Feds can do to bitcoin to make it lose its value. It's decentralized; there's nothing to seize or take."

Since Bitcoins are defined as "property" by the US Government, I believe it could seize the account(s) and anything else associated with those accounts just like what can happen when someone is accused of wire fraud. It may even open up the door for the Government to seize some of your other property and/or freeze your other accounts like what you sometimes will see in drug cases and some white collar crimes.

"All income is taxable. Even bitcoin investments. Also, bitcoins are tracked. That's what the bitcoin blockchain is, a history of every single transaction of every single bitcoin."

Someone may be tracking every transaction, but it doesn't mean all governments are tracking them. If governments are tracking them, then they may not always let the public know they have that capability.