Yes, the DC9099 is interchangeable with the 18V DC9096 battery.
Yes, the 18V line is interchangeable.
No. This will burn up your 12V tool motor. There are Dewalt 12V batteries available in multi packaging all over the place for about $35.00. Try googling Dewalt 12 volt batteries.
Hi Liz, yes the DC9096 is compatible with the unit DC987.
No, the DW953 is not compatible with the 18V batteries.
Yes, the DC9096 will work with the DC212B.
No I think, don't know, dewalt tools made in Mexico
Yes the do they want replace their old products with a new one
Yes, the price did go up from the last time I bought these batteries 4 years ago. They are pricey. It used to be they had a price for one battery, but if you bought the 2 pack the price would only go up by $10. The price now reflects a little better what a 2 pack would be.