The OB + Missionary gifting is a viable way of spreading religion to Theocratic civs. Tokugawa is always a problem, and needs more extreme methods like city gifting. I'm almost certain that the mapmaker would put Tokugawa in this game simply to further hamper the AP victory.
Keep in mind that in order to win the AP vote, we will need at least one friend to vote for us. The AP cheese method allows you to have easy friends by sharing their religion, in this game that option isn't available to us so we would need old fashioned methods.
The simplest way to make friends is certainly to share Hindu with them and hope they convert. If they haven't founded any other religions themselves then this is a good way to go. The problem then, is that they could actually come up as our opponent in the vote.
Not sharing a religion implies that we need to overcome the "different religion" negative modifier, since the alternative is they don't have religion at all = not any Hindu = no AP vote option. Unless of course they went free religion, but relying on the AI to tech to Liberalism and then convert of their own accord isn't much of a plan since it's all our of our control.
Factor in the extra -1 (or is it -2?) hidden modifier for the Aggressive AI.
The only AIs we could hope to get friendly are those that really love early civics like Organised Religion or Hereditary Rule.
I'm pessimistic about an AP victory, but we could certainly keep our eyes open if the opportunity presents itself. I like the idea of aiming to found many religions, as it ties in well with a Cultural strategy. FYI - the fastest cultural victory for these settings in the Hall of Fame is 1530 AD by Lowthercastle. I'm sure we could do better than that with a well focussed strategy... but will 1500 AD beat the Conquests and Dominations?
My opinion is this: I'd like to aim 100% for a fast Cultural game. If it turns out that it is in fact the best strategy for the map, then we win. If it's not, then at least we can all learn something about how to play a great Cultural game, something the SGOTMs have been lacking I think.