Power Supply amp doesn't match with adapter. Can I use the adapter?
Rather not. The specs of your display say that it might need 2A at times, and this would overload your adapter. This means that its voltage drops and the adapter might heat up, or break in the long run.

There's a chance those 2A spec are for the lower end of the voltage (5V) and it will pull less for 12V, but that would only be the case if you see a switching DC/DC regulator on the PCB. If it's a linear regulator, it will take 2A and just convert the extra voltage to heat.