yes, overall 6 is enough, no 2000 payment required
visa 487, before is around 3 months, now, you expect 6 months or more.
PR, my friend has been waited for 1.5 years still haven't got his PR yet, i don't know how long, but normally 2 years is your expectation, 4 years? no la, too long
if you have individual component that come with lower than 5, you may not able to grant the state sponship approval (according to the state sponsorship website), but you never know, cause some people still get the approval granted even they have 4.5, but things change all the time, pass not equal to present.....