I've only just moved to Singapore in the last year, and living close to the airport (Bedok Area), within walking distance to a MRT and bus station is invaluable for me. From my station to the airport takes 10-15 minutes max on the MRT, and taxis still only $10-12 including booking fee if you dont want to catch the MRT. Its approximately 30min on the MRT to the city.
Its also almost equal distance and very quick to get on both the ECP and PIE if travelling by taxi, and a $5-7 cab ride to places like Siglap and East Coast. Theres hawkers almost everywhere, but having a few close by makes life much easier. Rent in this area seems to be about $3,500 for a 3 bedroom unit at the moment from the places i've heard about.
Unfortunately I can't provide any information on schools, or car costs athough taxi drivers i've spoken to have said the tax you pay on cars can often reach 200% on the cost of the car when it arrives at the dock. Again, exactly how accurate this is, i'm not sure. As for domestic help, I have a cleaning lady who comes once a week and for $30 does 3 hours work and gets done in that time what would take most people all day. Not sure about live in maids.
As mentioned earlier Singapore is a VERY expensive place to live if choose not to adapt any of the 'local' aspects, (ie sometimes eating at hawkers, taking public transport, not living in typical 'expat' areas).
Hope some of this helps.