Yes, they can but they can only touch with their suction cups to taste. They can't just touch with their body.
Yes. Very normal. And you should. You should touch it as much as you feel the urge to.
cool and moist.
No however, you should never put the conditioner on your scalp. And comb the conditioner through your hair, then cool rinse it out. You won't believe how good your hair will feel after.
Actually, you probably don't want the "lowest PH". You want a shampoo and conditioner that is going to suite your hair (your hair's pH is between 4.5-5.5, so you'll want a conditioner with that PH). Being that no one on here can touch/feel your hair, I'd say you should talk to a stylist about the right shampoo/conditioner for yourself.
Depends... Has he been in light?
If you feel comfortable with that then yes let him touch them. But if you don't then don't let him. It's your body don't let any one touch you if you don't feel comfortable.
touch the surface of the brain how does it feel
The definition for touch is feel.
You can feel your legs by trying to move them or touch them with your hand.