Never played on Marathon.
I'd like to know how exploring the map works. Is it easier to explore on Marathon?
I gather that a Scout still moves 2 tiles on any terrain on all game speeds. If i started a Marathon game and my first production was a scout, would the starting scout uncover 3 times as much of the map before the 2nd scout was born, than a scout in a standard game?
Also as it would take more turns for the AI to build more Cities, wouldn't that starting scout be able to uncover more land around the AI empires?
You gathered right - and it does tend to distort the game when even the biggest home continent is completely revealed before 1AD. If Polynesia is in, for example, it's guaranteed to circumnavigate, contact every CS and coastal civ, and explore every isolated ruin while the other civs are getting their boots on. In human hands that amplifies what is already a ludicrously strong UA into almost guaranteed victory given the correct map type.
One thing that's still missing from Civ is a logistics model of any sort.