cost basis of a 1031 replacement property

[Daniel Blau]

I am shortly doing a 1031 on an investment property and really there's not a lot clear on how you compute the cost basis of the replacement property or properties.   

From best I can tell the cost basis for the new property  = the adjusted cost basis of the relinquished property + the mortgage on the replacement property - the mortgage on the relinquished property.    So say the adj. cost basis of the old property was $100k, the mortgage on the new property is $80 and remaining mortgage on the old property was $30k. Then the cost basis of the replacement property is $150k (= 100 + 80 - 30).   Is this correct ?  

if so, I have two other questions: 

1.  if I purchase several replacement properties under the 1031 how is the cost basis allocated among these several properties ?   

2.  If I do a cash out refinance on the replacement properties say within a "quick" timeframes like 6 months, does the loan from the refinance count as a mortgage on the replacement property and thus serve to increase its cost basis ?   

Tricky stuff.      

Thanks.    Dan from Jacksonville FL.