Keyboard Switching to Katakana After Pressing Space
Something I've noticed is that when I am typing using Hiragana, my keyboard will change to Katakana after I have pressed space. Is this because Japanese does not use spaces and the space would mean a change in character type?
Yes, typing with an IME takes some getting used to. I don't know if it's universal but at least with the built-in microsoft IME the space key will toggle between characters; hiragana, katakana and various kanji. Hitting the enter button solidifies that character/word/phrase as the one you want. To add a space you have to hit enter to lock in those characters first and then hit the space key when nothing is selected.
わたしはあめりかじんです "watashihaamerikajindesu (enter)" - all hiragana
私はアメリカ人です "watashihaamerikajindesu (space) (enter)" - all characters
私 は アメリカ 人 です "watashi (space)(enter)(space) ha (enter)(space) amerika (space)(enter)(space) jin (space)(enter)(space) desu (enter) - all characters with spaces between words
I've just started trying to type in Japanese and I noticed the same thing. Eventually I figured out that sometimes I was accidentally hitting alt-capslock while trying to alt-shift between English and Japanese. Alt-capslock switches to katakana, oops. Ctrl-capslock will switch back to hiragana (and shift-capslock will switch to romaji).
That's on Windows with the Microsoft and Google IME's anyway.