As far as i know, and somebody out there can corrct me if I'm
wrong...

The only real exclusions in the normal state of affairs, is to
avoid imbibing urine if you are on drugs, medication, etc.
Probably not advisable if you are in the process of getting
amalgams removed.

There have been many cases of people taking urine when in a highly
toxic state and it still benefits them.

There's nothing wrong with yellow urine, and in fact when you
urinate in the morning it ususally is yellow due to the concentration of hormones etc. - this is the good stuff.

What you are saying about not urinating in the morning, this suggest chronic dehydration to me. This probably is contributing to your health problems. Go to www.watercure2.org and read up on
this.

The salt thing people mention because urine is a good reflection
of your diet...the cleaner your diet, then the sweeter your urine.
I wouldn't worry about it. I take the equivalent of a teaspoon of
real salt (NOT table salt ) daily, and I get slightly salty urine in the morning.

I drink any urine - even urine a couple of hours old, if needs be.

Definitely check out the dehydration thing.