perkunas:
2)Halfway through the program I found it impossible to multithread and multitask, something you want to do after your 1st blinky.
Oh sure you can write a state machine, or some other trick but that's not true multitasking, confusing totally impractical.
Yet another modern PC programmer who does not understand state machines. No surprise there.
What Mike said, you need multiple cores to do "true multitasking". Which is possible with Arduino when you add MCU's... I'd go for SPI or I2C bus and some extra 1-wire bus comms as needed but the real question is why for a task like yours? Organized and written properly it should be well within the capabilities of an Arduino.