1. Moving apps to SD isn't - you only move small pieces of apps to SD, and leave a link to where on the SD card that piece is - in internal storage. If the piece that gets moved (and "moving" an app means moving lots of small pieces) is smaller than the link, you've just decreased the amount of free storage.
2. Rooting isn't "supported" or "not supported", some good software developer has to find a way to force the particular model phone, running the particular version of Android, into a temporarily rooted condition, so it can be permanently rooted. (Rooting requires that the phone is rooted - it's a catch 22 situation.) Evidently no one has found any way to obtain temporary root on that phone running that version of Android yet.
3. Unless you have a ton of stuff installed - apps, music, videos, etc., 32GB is more than enough storage space. The largest firmware I've ever heard of is way under 9GB.
So evidently you have something else wrong, or you have a lot of things still stored on the phone. (You've restarted it since removing everything, right?)