Need to get some worried weight of my shoulders... SSR airport advice

Hi all.

Well it's only about two weeks now until I leave for Mauritius, am very excited however a little nervous about Immigration once I arrive at SSR Airport. Since I am an Australian Citizen, what kind of scrutiny can I expect from Immigration since I will be coming to Mauritius for three months as a tourist. Keeping in mind I have a return ticked back to Sydney within the three months, well over US$100 per day to live off (should I travel with a recent bank statement?), a letter from my boss here in Australia to say that I will be returning to work in Sydney and accomodation with Mauritian friends (which I have a letter to confirm).
As I have been in Mauritius already this year (in Feb/Mar) for three weeks, will they be suspicious about why I'm back, and more importantly will they deny me entry?
As an Australian Citizen, I believe, that I can stay in Mauritius for three months as a tourist without a visa, and for up to six months in one calander year (but not all at once). Is this true? My Travel Agent did confirm this for me but I am still a little unsure as on the net there are no official periods of allowed stay mentioned, and in Feb my passport was stamped for two months.

If anyone can advise if I need to be concerned or what additional information I need to supply to Immigration at SSR than that would be great.
P.s. also whats the procedure with getting extensions? I believe this has to be done at the Passport Office in Port Louise? And whats the maximum extension they will provide me with, if I decide to take this option once I'm in Mauritius?

Thanks for all your help, again another awful long post from myself... but need to get some worried weight lifted of my shoulders.

Cheers.
Zack