I live in New Zealand and we share the same region coding as Australia. I can confirm that the 3DS is identical to the European release. SOMETIMES we get games and systems with AUS coding as opposed to EUR coding, but the only difference, as far as I know, is the included Club Nintendo codes which are region-locked. Yes, you can import a New 3DS and/or New 3DS XL from Australia and it'd work fine in Austria and Germany. Yes, you can change the console to any language. You would have to buy an AC adapter, though, as they are not included, just like with the 3DS XL in Japan.
Furthermore, as previously stated, handhelds to not conform to TV standards of PAL and NTSC, so that does not apply here. Most modern consoles, and all handhelds, have three main regions: America, Japan and Europe (including Australia/New Zealand). As I said before, sometimes the European ones are divided into Europe and Australia (EUR and AUS, respectively) regions, but are still compatible with each other.