I see Konohamaru getting senjutsu just like Minato did, and probably using the fusion with Ma and Pa. Naruto would probably teach him how to do so and also make him sign the toad contract which will give the the ability of summoning toads. He probably will learn how to summon Enma, the 3rd hokage's summoning, being the only significant heir of the Sarutobi clan close to Asuma's child. He will probably learn how to manipulate the five elements like hiruzen and also a teleportation jutsu like the 2nd's or the 4th's. Believe it or not, Konohamaru is smarter than Naruto when he was the same age, more skillful and better at using jutsus. He was taught the rasengan by someone like Naruto and could still get it. I bet after the war he would be able to do it with just one hand. He would combine the element he has affinity for with the rasengan and create another jutsu with Naruto's help. For a genin, his chakra sure is more than average. I bet he has more chakra than Kakashi and almost on par with Naruto of the same age. As Naruto's student/rival, he would get most of naruto's base jutsus and combined with his grandfather's library of jutsus, he would be a really strong ninja without any kekkei genkai or 'special power'.
The way I see in 6 years(about three years older than current Naruto)
Senjutsu mastery
Rasengan variants
A fire style-rasengan S rank jutsu
Mastery of 5 nature types
Frog summoning
Enma summoning
Kage bunshin skill
Shuriken skill
OP sealing techs from hiruzen's archive
A special shunshin or teleportation technique
Hiruzen mastered most konoha jutsus, I see Konohamaru doing better than that.
The way I see in 6 years(about three years older than current Naruto)
Senjutsu mastery
Rasengan variants
A fire style-rasengan S rank jutsu
Mastery of 5 nature types
Frog summoning
Enma summoning
Kage bunshin skill
Shuriken skill
OP sealing techs from hiruzen's archive
A special shunshin or teleportation technique
Hiruzen mastered most konoha jutsus, I see Konohamaru doing better than that.