Kenobi can likely hold him off for a good while. It would be a similar fight to him vs RotS Vader, except he wouldn't be as familiar with Maul's moves. He would need a "high ground" moment to pull off a win here.
I agree with even split...Kenobi is crafty enough to find openings and Maul is powerful enough to blitz through a good defense.
Depends. Maul is best off with the saber/darksaber combo. The dual blade lightsaber would hurt his chances.
If the battle takes place in a normal environment, Maul will start off brutal and keep going. Maul has absurd physical attributes, and won't be getting tired like most anyone else would.
However, as soon as Kenobi finds some tactical advantage that suits his stonewall style, he's got it.
"Don't try it, Maul, I have the high ground!"