I can see why you got attacked here. I don't know about the part about getting attacked because you had cities in between enemy lands. I certainly would have put some defense in my city, but probably a lot less than you think. Case-in-point... perhaps this doesn't apply due to some other patch of the game... although I doubt it... I downloaded a patch for the latest COTM in conquests..., I just completed an emperor-level game with the Maya where I basically had two warriors... yes *warriors* in every town *from basically the beginning until I discovered replaceable parts* (most aggressive setting for AIs). Yes, basically any intelligent player would have regarded my entire civlization as a sitting duck for centuries. I didn't get attacked and had NO wars throughout the whole game (no reloads for this... though I did reload once or twice in the ancient era due to not watching Chichen Itza closely enough). I probably would have upgraded to swordsman or medieval infantry, but didn't found a town with iron or could trade for it until the high middle ages.. then my iron source depleted a turn or two later. I did trade for it, but still didn't upgrade and didn't get attacked.
I did this basically through some strategies I've read around here about keeping the AI happy and using some tips I picked up from Drakan's "how to win on deity, builder style" article. I played my emperor game on a standard sized map. I had RoPs with EVERYONE, and traded for gpt as much as I could (and traded for luxuries, of course)... sometimes selling technology. I rarely gave gold away to keep AIs happy, except at the very beginning when no AI could afford a gpt. You had no RoP... it could have actually helped though... for the situation with the English. Although, perhaps not all too much, especially looking at your game. A RoP will improve your reputation as long as it stays in effect. Of course, the downside of such comes as that an AI might easily war with and defeat someone you don't want them to, and that you would severely damage your reputation if you attacked someone while it stays in effect. From the looks of your game though it seems like you had quite a few wars throughout the earlier game, long before you know where your resources lied, along with some genocides. So, even though I don't really play this way... I ask... why didn't you just keep going and go for domination or conquest?
You also said that you wanted a space race victory. Perhaps you didn't decide this from the beginning, so perhaps I say the following in vain. From what I've read, for that type of victory you want to have a high tech rate, and slow down the AI. I don't know how to provoke two AIs to fight with each other, but if you want to have a high tech rate, I certainly don't see a need to conquer more land and increase corruption... at least in most cases. With a space race victory goal, personally, I wouldn't even start a war for coal or oil. I'd only start a war for aluminum, uranium, or rubber to build those SS parts... and then *only* fight offensively to take those resources. The rest of the time I'd fight defensively. Although, maybe one would need coal in some games. Maybe you just started playing without a victory condition in mind. Nice game... and thanks for posting.
), so you should really think of it as player 1 vs player 2 + player 3... ... + player xy 
I still have some Dromons...