I love playing the 18 civ earth map, I dunno why its so fun its just so interesting to see how the world develops.
I usually tinker the the worldbuilder to help out some of the weaker civs. I always put Izzy on the coast, I put the Incans on the coast & remove a few mountains so he can access the inland ( although this rarely helps, he's always helpless ). I change the egypt desert horse to a plains horse & desert hill in capital to plains hill ( this makes egypt fairly strong ) I will also improve mansa's capital a bit from now on after seeing how bad his start is today.
I never rush the AI before construction on this map cause its way too easy ( even giving the AI archery & archers doesnt help ).
I played a game last night as Rome & shipped my army of cats, war elephants & praets over to Africa to grab Egypt & Hatty must of seen the writing on the wall cause she volunteered to be my vassal. I accepted & instead crushed Mansa with Russia & Saladin joining me on a war on the heathen buddist. Thats the 1st time I've ever seen a civ the same size & tech parity vassalize vouluntarily. ( it ended up being a huge mistake as she ended up beating me to many wonders )
If I play as a european power I'll usually beeline astro in an attempt to save america from aztec extermination, at least 90% of the time America is either gone or down to 1city in northern canada. I even gave America a super capital once ( 2 cow, 2 gold, etc ) & when I found North America Washington was now an aztec super capital.