Not so, leeneia--ABC can do everything you've mentioned either through facilities of ABC programs (most of them FREE) or by tweaking a line or two. They're easily modified (without requiring special software), and they retain all aspects of music notation (crucial for printing scores), which MIDIs do not.

It's because ABCs are so flexible, while retaining all notation artifacts, and can be posted as simple, concise text, that I like to use ABC. Even better if one has both--MIDIs for ease of sampling, ABCs for generating scores and customizing. Of course, if you have the ABC, you can always generate a MIDI, in whatever key you want.