Let me try and answer each of your questions in turn:
1. The Indian population is quite low in Perth. The city is not quite as cosmpolitan as Melbourne or Sydney where you'd find a more diverse range of people, including Indians. So it would be hard to say there a particular areas or suburbs popular with the Indian community.
2. Average rental prices in Perth are around AUD 600 per month for a 3 bedroom family home. For more on housing in Perth read the Expat Arrivals pages on Accommodation in Perth and Areas and Suburbs of Perth
3. The cost of living of for your family will depend on your lifestyle. Perth is cheaper than the bigger Australian cities. You can use the Cost of Living in Australia page as a a guide to help you draw up a budget for the family.
4. The cost of school fees will depend on where you choose to send your daughter to school. Private and International schools in Australia are experensive and can cost up to about AUD 25,000 per year. The cost of public schooling is much less but varies from area to area. See the Expat Arrival's Education and Schools in Australia page for an overview of schooling options in the country.
5. The biggest expat employers in Perth are found within the mining industry. However, as long as you have a valid work permit, good level of English and a strong CV you will be treated equally to an Australian applicant.
6.The cost of relocation will depend on wether you plan on shipping stuff from home to Australia, etc.
7. You will need to have private health insurance for yourself and your family in Australia. However, you'll be pleased to know that the standard of healthcare in Australia is excellent. Read the Healthcare in Australia page for more details.
8.For information on climate take a look at the Weather in Perth page.
9. Finally, Australia as a whole is pretty safe. I wouldn't say there are any particular threats for Indians in Perth. Obviously, you should excericse caution whilst in busy areas or walking around at night. But generally, expats feel relativley safe in Australia.
I hope these answers and our Perth City Guide are useful for you. Good luck.