Questions - Work, Visa and Property

Good afternoon,

Last year, I spent 6 months in Cambodia and fell in love with the country. Here in Australia, I work as a water quality consultant and we are looking to expand internationally. Naturally, I jumped on the opportunity to expand into SE Asia and particularly into Cambodia.

I'm intending to move to PP around the end of September/ start of October but I thought it would be wise to ask a few questions about business requirements, possible visa requirements and the like. So I have a couple of questions to ask.

Considering that my business is an international one based in Australia, we would look at doing work for certain clients in Cambodia. Living there, I would do the work, but wouldn't be paid directly by these clients.

1) Do you think it would be necessary to set up the business in Cambodia, if the money for services is going to a business based in Australia and my monthly salary is being paid by a business in Australia?

2) If its not necessary to set up the business in Cambodia, how would you advise going about visa and work permits for long-term stays in the country to conduct this work? How does "freelancing", as it were, work in this regard?

3) This is more of a personal question - the mum of my Khmer girlfriend wants me to buy a house in Cambodia. I'm aware of laws regarding strata titled ownership for foreigners and being unable to own landed properties. One of my missionary friends thinks that it may be possible to own a landed property so long as it is 51% in a locals name (like my girlfriends). Does anyone know anything about this?

Looking forward to hearing your responses! Thanks very much
Nathaniel