Tuning (and I mean real tuning here--calibration is a more accurate term) isn't just timing and A/F. Pick up any IC Engines book and tell me that is simpler than an engine. It just isn't so. Just like an operating system, an engine has many parts that have to work together and they all affect eachother...and it can't crash or have to reboot it every once in a while :P Seriously, though, everything you are looking at is just touching the tip of the iceberg.
Soren Faaborg Phuong on the Amish < GotRice_ > they get all horny when I show them electronic stuff