Arduino Mega 2560 IO pins

Greetings!

i have a very simple question actually. Of 53 digital I/O pins on the mega are there any restrictions of using them? For example i have pins 50-53 reserved for SPI, a SD card reader to be precise, pins (2,3,4,5,11,12) for a LCD screen and pin 9 for a speaker. I know that pins 0,1 are for communication aswell as 14-21. But could pins 14-21 be used as normal I/O pins, since i will not be having a I2C or UART communication when the final program code works? Or am i obligated to use pins 22 to 49 for 11 sensors and 10 mosfets?

But could pins 14-21 be used as normal I/O pins

Yes.
And the analog inputs can be used as digital I/O as well if needed.

The analog inputs are digital pins with the added functionality of being connected to the ADC mux for analog reads.

Some pins are limited, such as not supporting PCINT.

The datasheet at www.microchip.com gives the full details of what all pins on all ports are capable of.

Thank you for the help!