Is PIC suitable? PIC controller has multiplexed ADC inputs, which you can use for paralleling Analog to digital conversion. But keep in mind that these are multiplexed inputs not a stand alone inputs, you have use one ADC input at a time, you can not use more than one ADC input at a time. As these are builtin features of PIC, thats why they have limited option. ADC voltage will not be more than 5V DC, if your analog signal is more than 5V DC, than you have to use voltage dividing circuit at the ADC input to lower analog voltage in between 0 and 5V DC.
1) You can use PIC controller for measuring temperature of any thing with the help of commonly available temperature sensor LM35.
2) You can measure pressure and moisture values after interfacing pressure sensor.
3) You can make your own Voltmeter, Ammeter and Power meter.
4) You can make Intelligent Battery charging Circuit with ADC