Rental of apartments have dropped over the years, so the figure here a bit high, if you shop around, its easy to get a average size apartment for less than SGD$2k.
Taxi to airport is non-issue, cos company pays. If you stay in the Eastern part (NEar SIA Training Centre) Taxi to airport probably cost about $6.
Cars in Singapore, that the expensive part. A mid size 1.5l Mitsubishi Lancer cost about $70,000, add in road tax of $1000 annually, Insurance of $1500 annually, Petrol at average $1.20 per litre, you'll burn money faster than a 744 burning its fuel.
(All figures in SGD). Forget about your Lexus or BMW, its cost more than $150000 in Singapore.
Salary in SQ is not the highest, but beats most regionals hands down.
Main problem is adapting to the management style here. Unions here are unlike the West, where you can don't fly and go on strike to drive your message through, do that in Singapore and they'll pack you in the lastest A345 to send you home the fastest possible time.