xx Cookie-Boots xx
Alright, let's examine "uselessness".
-Ino played a pivotal role in taking out the Kin/Gin brothers
-Zetsu provided intel on all the battles ever to Tobi and created a clone of Kisame so they could capture Yamato (though that wasn't the initial aim xD)
-Sakura killed Sasori
-Choji took down Zombie!Asuma.
-Tenten used that Bananafan. Didn't do much, but it was awesome.
-Hinata... what did she do again?
-Shino... what did he do again?
-Kiba... what did he do again?
-Kurenai went in the kitchen.
So, in a nutshell: Team 8.
Every single one is useless.
Seeing as how Team 8 happen to have abilities used for reconnaissance they are not useless they are, in fact, useful. They also, like most other characters, happen to be underused.
Kiba was useful in the Rescue Sasuke arc, as it was his job to let the others know if they were being followed or if there were any traps. He also had a part in tracking Sasuke's whereabouts for Sakura when she wanted to kill him. I'm also sure he had a part in finding Itachi during the Eight Squad search for Itachi arc.
Hinata isn't really a character I care about, so my memory of her is limited. I do find her to be far Naruto-centric. Which is a shame. However, she does have a 10 kilometre vision range and having such vision is, in itself, useful.
It's interesting that you remember and note that Ino had an important role in taking out the Kin/Gin brothers, but seemed to have forgotten/ignored that Shino had an important role in finding out how Tobi's teleportation ability worked. It was also noted by Kakashi that secret clan techniques, such as the Aburame, are useful in finding out about unknown techniques. He also happens to come from a clan who controls insects that feed on chakra. In case you've forgotten, chakra is a very important part of being a shinobi.
Every single character is useless depending on the situation or task. Also, don't think that 'cause they have a highly useful ability they are not useless. If they don't have the will to use said "useful" ability, they can be counted as useless.
Most of the people replying to "who is useless" topics don't seem to know the actual meaning of the word.
xx Cookie-Boots xx
If Shino didn't exist, would the story be much different?
He's a side character. He plays the role of extras who make up the story. That question has nothing to do with being useful or not.