Kimimaro Kaguya
First i'll tell you why people shouldn't underestimate Kimimaro, which is a grave mistake seeing as, he was the next vessel of Orochimaru if it wasn't for his sickness he would have been perfect.
Now here is why I believe orochimaru wanted Kimimaro's body.. Now let's go back to the Sage of six paths, he had two sons the younger brother (Body), and the older brother (Eyes).. Here's what I think
Senju>>>Uzamaki>>>Kaguya - These are all what I believe to be the (Body) of the sage..
Rinnegan>>>Sharingan>>>Byakugan - These are all what I believe to be the (Eyes) of the sage..
Now back on topic, I believe that Orochimaru actually wanted the Body of the sage, because he possessed neither of the two.. But if he had the body, he could easily get the eyes of the sage from an Uchiha/Hyuuga. So after Orochimaru sought out Kimimaro the (Body), Kimimaro had later on gotten sick by some unknown disease well, that set back Orochimaru's plan until he could get Sasuke (the eyes).
Proof from the manga Orochimaru wanted Kimimaro's body, and was the perfect host at the time to take out the leaf village..
Kekkei Genkai
Shikotsumyaku "is the kekkei genkai of the extinct Kaguya clan, which gave them the ability to manipulate their own skeletal structure (their osteoblasts and osteoclasts). By infusing their calcium with chakra, they could manipulate the growth and properties of their bones to their liking".
"The ability seems to be rare amongst the clan members, as Kimimaro is the only known user even prior to his clan being eradicated".
"The main capabilities of Shikotsumyaku is allowing the user to manipulate the speed of their bones' growth as well as the location of calcium deposits. This allows them to create weapons of bones that can either protrude from any part of the body, or pulled out and used like hand held weapons. The user was also able to create armour of dense bone underneath their skin".
"They can even fire pieces of their bones as long-ranged projectiles. Any bone that they remove from the body immediately regenerates, as does the skin that is damaged when the bones are removed. Users can increase the density of the created bones, making them stronger than steel. This not only makes the created weapons very powerful, but also makes their bodies virtually indestructible; the bones can withstand even a chakra-infused blade, which is usually enough to cut through anything."
This is why "Orochimaru coveted this ability greatly, stating the kekkei genkai granted the user an impenetrable skeletal frame, which can resist any type of physical attack. In addition, should a Shikotsumyaku user ever go on the offensive, they could instantly turn their bones into the sharpest spear. Overall, the Shikotsumyaku is considered to be the ultimate taijutsu ability, which is held in high regard".
Cursed Seal
"Like many others of Orochimaru's closest followers, Kimimaro was given a Cursed Seal, which granted him tremendous power. He bore the Cursed Seal of Earth, which is said to be equal in power to the Cursed Seal of Heaven, and both Seals are said to be the strongest amongst the ones used by Orochimaru. When in his Level 2 form, Kimimaro's appearance was similar to that of a dinosaur, with dark grey skin, six large bone spines protruding out of his back, and a long bone-spiked tail. Jūgo stated that Kimimaro had great enough skill with the Cursed Seal that he could do a partial transformation. Furthermore, Kimimaro's fighting style changed after entering his Level 2 state: he became much slower, but his strength increased to the point of smashing Gaara's Shield of Sand with ramming, and his skin became thicker and harder, making it impossible for even Gaara's sand to penetrate it".
Reading this, I would confirm that Kimimaro could probably switch back and forth from Lvl 1, and Lvl 2 for a combination of speed and strength which would give him an advantage in most situations..
Kimimaro isn't a fodder
This is what doesn't make sense to me, is when people deem Kimimaro as a fodder just because he "lost" to Naruto+Lee+Gaara, when really he lost because of his sickness..
"After Gaara insulted Kimimaro's loyalty to Orochimaru, he used his sand to bury him two hundred metres below the ground, where the pressure can crush even steel. Kimimaro, however, used the last one of his dances to turn the battlefield into a forest of bones, that Gaara and Lee barely escaped by hanging onto a small cloud of sand. Fuelled by his hatred of being insulted, Kimimaro emerged from one of the bones, and prepared to strike the two at point blank range. However, he finally succumbed to his illness just before he could kill Gaara, who was already out of chakra, and died. Gaara later came to the conclusion that no-one can defeat loneliness, even if it means to care for a person like Orochimaru".
If you read that, it obviously states he lost because of his sickness, not because he couldn't kill Gaara who was chakra drained anyways.. So just wanted to clear that up Kimimaro isn't a fodder.