Å and A are not at all the same letter. Although I agree that using characters outside of the ascii set for naming projects on the internet is probably a bad idea. If I had to translitterate Ålenkå to Latin chars, it would probably be Oolenko, but even that's not really that close. The Latin alphabet has a horribly limited set of vowels.
Yep, perfectly typable. Though I did have to look up the deadkey for ˚ as it's not a diacritic I use often (Option-K on the Mac OS X US Extended keymap; on Windows or Linux US International keymaps you can do it without a deadkey as Right-Alt W, or on the Mac US keymap as Option-A).
I highly recommend that people use and learn the "extended" or "international" keymaps on their system, so they can learn how to type these sorts of characters easily. As more and more systems are Unicode enabled, and you interact with more people internationally who would prefer their names to be spelled properly, it's a useful skill to have (and doesn't really take much work).
Alphabets transmit words, much less so sounds.
In English, that is. Some languages using latin script always use the same sound for the same letter (how it should be done, IMHO).
A and Å are different letters, and can't be substituted for each other.