[Spoiler] There's no denying it now
It has been heavily foreshadowed by Kishimoto that Obito is in fact, the new generation's Sage of the Six Paths. He has done this through mirroring Obito's feats to the Sage's and clever use of subtle symbolism and characterization. If there is any denial of it now, I hope this thread will clear things up.
Anyways I'm going to try to keep this short and simple
Main Premise- Obito's role as a villain is to complete The Moon's Eye plan (and has been the sole character that has moved the plan forward), and create a new reality. From Obito's many speeches about Rikudou, the ability to create is what defined the Sage. Obito's goal is to have the power to turn his imagination into reality, which means his abilities would have to rival the Sage's, to work as the main villain.
1. It was hinted that Rikudou was a great bringer of peace. Obito is the one that brought on the greatest war in ninja history.
2. Rikudou separated the Bijuus from the Ten Tails. Obito is the one that brought the Bijuus back together to form the Ten Tails.
4. Most likely because he used his Izanagi, but not necessarily to not die. He described the power to Konan as the ability to make imagination into reality, and that it was the Jutsu Rikudou used to "create". At this point it doesn't seem far-fetched to assume that Obito used his Izanagi to mold reality to him becoming the Juubi Jinchuuriki, when it seemed like an impossible feat from his position.
Conclusion from feats- Obito is meant to be an anti-S06P or a corrupted Sage of sorts, and will represent the current generation's Sage until the end of the manga.
Supporting characteristics from theming of Obito-
Yin-Yang is a common concept in the Naruto series, however, two characters stand out as being constantly characterized with the dualism concept as part of their single character: Rikudou and Obito (Other characters are a part of this concept, but usually they are only the expression of Yin or Yang, not both)
For a more detailed version of Obito's dualism analysis, refer to my other thread:
1. Dualism Symbolism-
-Obito's body is exactly half senju, half uchiha
-Obito has the Rinnegan (Sage's Eye), and Sharingan (Curse of Hatred Eye)
-Obito's white mask design is the Juubi's eye, a visual combination of both the Rinnegan and Sharingan
-Obito was the main narrator for the most important stories regarding Rikudou and his sons. Kishimoto did not choose this by chance.
-In the fight vs Kakashi in more recent chapters, Kakashi points out that Obito is trying fighting his younger self through trying to deny Naruto and Kakashi's philosophies. Obito's elder curse of hatred is metaphorically fighting his younger will of fire self. A familiar theme here...
- Obito stated that he will manipulate and be the context for the Naruto and Sasuke fight. Similar to how Rikudou's choice of successor was the reason The Elder son fought the Younger and carried on the Senju vs Uchiha legacy.
-Obito's constant will to deny reality and recreate his own is his motivation as a character. His motivation has always been to be Rikudou's successor.
What it all means:
The series buildup has reached a critical point revealing Obito to be the villain counterpart to Rikudou, and from here on out we will see the conflict buildups brought to resolution between Hashirama and Madara, the Naruto vs Sasuke fight, more attempts to save Obito's younger will of fire, and Naruto becoming the true successor to the will of Rikudou and Obito. Time to just enjoy the ride
tl;dr: Obito is the main villain and counterpart to Rikudou that Naruto must overcome.