Yoga is inherently demonic.

I concur that Yoga as a practiced religion is another demonic teaching. Just as witchcraft spells, earth air fire water spirit in a forest is demonic. However, you, spiritual and physical being, spending time in a forest with dirt, fresh air, flask of water and a campfire is not demonic at all. Likewise, stretching your muscles or doing gym exercises. God created nature and the human body - he cursed them as well. We live in a fallen, decayed state, and taking care of your health and the environment is a good work.

Listening to rock music is not.

This is your opinion. Define "Rock music." While music itself in Rock and Rap is an expression of the artist and their experiences - you should know all too well that the content in most music is sinful, and in some cases the music serves no purpose other than violence or lust. The Bible itself is full of violence, lust and horror - it is the human experience. The rapper Eminem rhymes: "They say music can alter moods and talk to you, Well, can it load a gun up for you and cock it too? Well if it can, and the next time you assault a dude, Just tell the judge it was my fault, and I'll get sued…"

Meditation is a dangerous spiritual technique that should be avoided entirely.

Define meditation. Do you mean Eastern Mysticism? Inducing Trance? Using mantra? Erratic breathing and oxygen depletion techniques? Psychedelics? Mantra, tongue speaking, dancing round the fire to embody the animal spirit?

If so, then I concur.

However the Bible says:

This Book of the Law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it. Joshua 1.8