In short, yes, you can live outside of Australia and be a shareholder of an Australian company. You will need a Shareholders Agreement. Different rules apply if you are seeking to operate a foreign company in Australia.
Other things to consider are whether you are also a foreign director of an Australian company. A proprietary company must have at least 1 director and that director must ordinarily reside in Australia. A public company must have at least 3 directors and 2 must ordinarily reside in Australia.