5'6"
Nothing wrong with that.
it is not normal... it is gross if you don't take a bath or shower for a long time because you will smell and be gross.
it is just normal bath water
It is normal chihuahuas usually shakes and it could be hot.
21 inches normal height from floor to top of bath but check the panel height
It could be lice or parasites. Make sure they have access to a good dust bath.
some time
You find normal gems in shaking ground in most caves. I find that shaking ground is more common in Twist Mountain. Also, if you wanted to find another gem, for example, a dragon gem, it is exactly the same.
3 bed room, 2.5 bath
A radiator has rubber mounts that hold it in place. There should be no shaking from the radiator unless one of these mounts is defective or the bolt that holds it on is loose.
If you are under the age of 70 and are shaking too badly I would make an appointment with a neurologist.