Could it be possible that you are receiving inaccurate temperature readings? I am in no way saying your wrong I am simply asking for some verification of temperatures.
The OP is asking for help with curling and warping you gave him your experience as a solution but failed to mention that it may be the exception to the rule.
It's simply impossible to prevent shrinkage of ABS as it cools so the best we can do is manage the problem. I think that for you lowering the bed temp has helped maintain a more even temp across the entire print.
Back to the OP here is my effort to help.
For (dare I say) the rest of us an increase in bed temp would be helpful.
Ensuring everything in the (enclosed) printer is up to temp before starting a print would be helpful.
Using hairspray, Glue stick or ABS slurry would be helpful. Although I am not a fan of Slurry or Glue stick they do work.
Squishing the first layer a little more would be helpful.
Decreasing Extrusion width for the first layer would be helpful.
Ensuring your bed is flat and level in relationship to the extruder (I understand Davinci's have auto level) would be helpful.
A screen shot of how to change bed temps for first layer and all others if using Slic3r would be helpful.
It is my strong belief that there is a good chance you are using PLA instead of ABS. Perhaps the filament is mislabeled as you mentioned the plastic is "literally turning into liquid" on the bottom layers. The only logical explanation for this is that you have PLA or your bed temp readings are way out of whack.
Also would like to mention that having your bed turn down to 60C would most certainly cause your print to come loose If it is indeed ABS.
I hope that helps.
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