We sold a plot of land overseas which we have held for many years and are expecting a huge Capital Gain. I guess this will be considered "an investment"

If our tax bracket in 2014 is 10 or 15 per cent, what will be our LTCG? WILL IT BE ZERO? I read this somewhere and wanted to verify.

In case it is not zero, can we sell our principal residence in NJ(we have lived everal years) in which we expect a loss and reduce our LTCG by the amount of loss? Can we club together these categories?

Can we take credit for the taxes we are required to pay overseas on the sales of land via Form 1116?

If we pay 100 per cent of 2013 as "estimated taxes for 2014", are we safe? Are we required to pay any more considering the huge LTCG?

Any insight will be appreciated.