I have a wide experience of software development for AVR, STM8, STM32, LPC17 microcontrollers.
Concerning the project:
buzzer alerts - to clear up, I ask you to draw the time diagram alerts with the specified temporal intervals.
sound alerts - will be better if you write which frequencies it is necessary to reproduce.
button logic and press detection - at me isn't present questions, everything is clear.
interface with 10 segment LED bar - LED bar is connected directly to GPIO or through the register?