Strategoc dilemma

[Prospero]

I started playing a game last night where the starting position and layout of the land had me facing an interesting strategical dilemma, and I’d like to hear your thoughts on it.
I started out on a small stretch of land ( it was a pangaea map ), connecting the two main bodies of the continent. While scouting, I discovered all of the other civs were located on the northern part, while the southern, somewhat smaller part was only inhabited by barbarians. In other words, a huge slab of land all mine for the taking, since my city controlled the chokepoint.
This ment I had to refuse all offers of open borders though, so no one could pass my borders and found a city. Then again, this has its disadvantages, since I won’t be able to establish trade routes with other civs, which means a considerable loss in money. Also, I always like to explore other civs territory to have an idea what potential they have, in order to have an idea who to make friends with and who I can afford to be on less friendly terms with.
What would you do in this situation ? Close your borders and have the advantage of being able to comfortably grab a great deal of land and resources, or opening them and having a better economy and potentially better diplomatic relations.

 

[lomis]

I would open them, and IF a settler of a diffrent empire wants to get through your main city you can simply break the open borders treaty with that nation.

But normally the AI needs a lot of time to spread out, and if the next 10 - 15 tiles are yours no opponent settler will come.

 

[Prospero]

To my experience, the AI does spread out to places you would normally not expect. I was in a more or less similar situation once, on a peninsula. I was spreading out slowly, thinking I had time since the AI could not cross my borders, but it appeared two civs had settled a coastal city by the time I reach the edge of the peninsula.
Taking the continent will take time, so I absolutely need to avoid any settlers passing my city. Also, I don't like being forced to attack. I prefer to choose my adversary

 

[Loammi]

I keep my borders closed in your situation until I have the land that I want. Then I open my borders to revive trade. Typically as long as I have developed some economic infrastructure I don't see a huge loss to my economy long term.