You have 20 IO pins available.
18 if you reserve D0, D1 for serial interfaciing.
Commit 11 or 12 to the display, leaves 6 or 7 free for the accelerometer.
Is that an analog outout device> I2C or SPI device?
If you need to free up pins, you can use a shift register to write the segments for the display, and gain 4 or 5 back that way (instead of 7/8 segments, have a datapin, clock pin, and latch pin for most shift registers). If you use a 2nd shift register daisy chained with the first, then you can gain the 4 common anode/cathode pins back also.