Orochimaru wasn't the type to care about your loyalty and crazy devotion for him. He just needed you to get the job done, and as long as he can control you, he doesn't care. In translation as long as he's stronger than you, he will keep you as his person.
That's why he was still able to get together with Orochimaru even without that crazy devotion previous Kimimaro had in the original series. There were a number of people under Orochimaru in the previous series, but only Kimimaro had that crazy devotion and loyalty, that got him nothing in the end by the way. That's why he was sure that he doesn't have to emulate the original behavior of Kimimaro around Orochimaru.
Orochimaru trained him in the taijutsu department and as well as basic chakra knowledge. He quickly developed the techniques he used in the original but on a smaller scale though, because of his young age. His strength will grow with age now.
He soon met with Kabuto too and asked him to join them in their research. His interest was Orochimaru's DNK research particularly. They all worked together nicely but he expected that Kabuto and Orochimaru conspired and will take his body in the future, to be Orochimaru's new vessel.
That will never happen though, because his illness would soon start showing. That will happen in the future, before the Otogakure conquest they have planned. It will happen after he gets Orochimaru's curse mark. Orochimaru was still working on it now, as just recently he met Jugo.
Kimimaro also met with Jugo, they also became "friends". But for Kimimaro there is no place for friends in this life. They will only drag him down and stop him from getting stronger and having more fun battles in the future.
He didn't want Orochimaru's curse mark and his powers. So, he had only a couple of months before the Otogakure conquest start, before he would be forced to take it.
He was currently working extensively on his DNK research in the lab. He started classifying and sorting the genes in his body as soon as he started researching this subject.
He soon realized that 25% of the genes in his body were different from normal humans. He doesn't know how to explain it, but those 25% were definitely not from normal human origin. It felt like they were alien in origin.
That's where the problem lies, he thought. His human genes and his alien genes were not compatible with each other. Resulting in his weak constitution and genetic defect, and later in the series, illness.
He also had one crazy theory. That 25% of his genes were from the Ōtsutsuki clan people.
That's why Uchiha people also had similar health problems when they overused their Ōtsutsuki Uchiha bloodline, with Mangekyo Sharingan. It was simply not compatible with their other human side.
That's why original Kimimaro also got sick, he overused his Kekkai Genkai same as Itachi Uchiha who overused his, resulting in both of them suffering from the same illnesses.
Uchiha people found a way to get rid of this problem by implanting a different Mangekyo Sharingan on their original one, thus resulting in 50% of their genes changing and now becoming Ōtsutsuki in origin.
But it's different for Kimimaro. His clansmen were all dead, not to mention his Kekkai Genkai is different than Uchiha's so he can't directly transplant the eyes of his clansmen into himself.
Closes people to his clansmen were the ones from the Hyuuga clan. He theorized that both of them were from the Homura Ōtsutsuki branch and transplanting their genes onto himself can make a balance of his genes and cure him in theory.
He found a way to transplant genes a while back. And he can directly take the Byakugan and place it on him. It's just that he can only steal from the main branch due to curse mark restrictions. It will be extremely hard accomplishing this, but this is the only way.
He first needs some Hyuuga genes to make it 50% for himself regarding Ōtsutsuki genes. Then he will transplant Byakugan from the main branch. This reminded him of a lot of the practice of acquiring Tenseigan. Who knows, maybe he even get a Tenseigan in future, when the time comes?