He would have been extremely OP and would have been capable of defeating Sage Naruto
-His Susanoo would have been far more powerful with Nature Energy (especially Perfect Susanoo).
-His Chidori would have been enhanced as well (like the time during Naruto Vs Sasuke Part 1).
-His S/T Technique would've probably had a lesser restriction time and be more advanced.
-He could have had two Rinnegan by now if he had the Curse Mark
-He would have still had wings (both even if Deidara destroyed one)
-Amaterasu would be even more Powerful, and quicker to use in battle.
-He might have been even been better at using Genjutsu (but this one I doubt)
If Current Sasuke still had that damn curse mark he could've actually been equal/above to Current naruto.
Natural energy doesn't make jutsus stronger, senjutsus does and CM was weaker than imperfect SM and Kabuto called it "pretension trick".
The Chidori being enhanced wouldn't help when Naruto's jutsus are enhanced with Senjutsus+Bijuu chakra and yes Sasuke is currently using Senjutsus much greater than CM due to it being from the Sage.
CM wouldn't do much for his Rinnegan when the senjutsus he's using now is stronger and no he wouldn't have 2 rinnegans.
A bit sad you don't know the senjutsus chakra he's using now is >CM which is nothing compared to SM according to Kabuto. Naruto would still be stronger anyways, BM alone showed to have more power than PS and EMS Sasuke was even jealous of BM Naruto power when he wasn't even at full power (he had to borrow chakra from Minato/Yin Kurama).