I think, the scenario played out very well. The Jungle-Elephant was very helpful, especially in the later stages, when the front had moved way beyond the range of my road network. I was able to keep moving quite swiftly despite the bad terrain.
I stopped research right after Chivalry. I think, the scientific AIs got only one of Feudalism/Monotheism, so I had to research 2 medieval techs. But I slowed Chivalry down on purpose for like 10 turns in order to first build up a decent horsemen stack while accumulating some cash. The reason was that once Chivalry was completed there would no longer be the possibility for any upgrades. That's the major disadvantage of the Elephants requiring no iron.

Cash was later used for short-rushing and rushing some regular Elephants directly at the front line, as well as rushing settlers in the out-lying towns.
Up to Chivalry I had been settling peacefully (there simply was no target within reach yet...), but with the completion of Chivalry, I immediately upgraded a dozen horsemen and started rolling over Babylon. I could have prepared that a little better by rushing barracks in a border town and stationing my horsemen there already, so I guess I lost 2-3 turns, when my Elephants first had to move from the core city, where they got upgraded, to Babylonia... (At least I already had an almost complete road in place...)
From there I split and took on Arabia, Egypt and Osmania, always making sure to spare those cities that were currently building Artemis (Mecca, Theben and one of the Osman first-ring cities.)
Which AI proved to be the most competitive?
None...
Tobacco was not a luxury resource in my game?!

And another strange glitch: my first and only leader (Chandragupta) had 4 movement instead of 3. Cotta already reported, that Crusaders had 2 movement instead of 1.
The improved worker was of course very powerful. Because of the extra movement, it was more like a 100% bonus speed than 50%: an ordinary worker can put a road on a tile in
4 turns: 1 to move onto the tile and 3 for the road. The Indian worker was able to set up roads at
2 turns a piece: 0 turns for moving onto the tile and 2 turns for completing it!
This little bugger certainly was the most powerful unit of the game.
Taj Mahal was very helpful for earning some extra cash, but not because of the 5% interest, rather because of the extra happiness! At first I thought it would not be needed in this game, as 5 luxury resources were within easy reach. So I just built it because it was "in the spirit of this scenario". But afterwards I was glad I built it: in the beginning I did not yet have Marketplaces everywhere, so would have had to run a higher lux rate despite the 4 luxes I had at that time, and in the later stages of the game I always had at least one source of, so despite 5 luxuries and Marketplaces I would have had to run like 40% lux rate. With Taj Mahal I got by with 10-20%, and once I managed to hook up the gems in the very north, I was able to run 0% lux rate in the final stage of the game.
The 5% interest were not useful to me, because I always rushed away my entire treasury every turn. On the bank account the gold doesn't do you any good, but in the form of 2-3 extra reg Elephants directly on the front line it can make a huge difference...
I think the "favorite government" feature does not have any effect on the human player, only on the AIs, doesn't it?!