Does ultrasound a complete blood tests being perfect rule out liver/galbladder problems?

Usually yes: Sometimes there is sludge or nonopaque cholesterol gall stones in the gall bladder causing symptoms and the sludge or stones won't be seen on ultrasound.

Nothing perfect: Despite all the knowledge and technological advances, test results for any disease must be combined with a detailed history and physical examination. For gallbladder disease, while unusual, it is possible to have normal tests and still have a problem. Rarely, and if symptoms are bad enough, surgical removal can be an option, but only after careful risk/benefit analysis.

No...: Even a negative gallbladder us should be followed up by a pippida scan to check on how well your gallbadder is functioning. If the ejection fraction is low, they will take out your gallbladder and symptoms generally go away. If you are having symptoms, make sure to not eat any fried or fatty foods, or you will suffer the "pain of the evil gallbladder". Amylase ; lipase blood test might help.