Guys, I see a lot of people saying line up "as early as possible," how early exactly is this? 7am?

Also, if I live in SS2 does it make more sense to go throng with the tons of ppl in Damansara, or take a long drive to Kajang instead?

Also2, do you guys think Singapore will also require the 6months validity thing?

It varies from country to country.

Last week I traveled to Botswana and South Africa with my passport having only 5 months validity left, didn't have any problems.

For countries that need visa, they don't care where you arrive from. So if your question was "Let say if I depart to Taiwan Country X that needs Visa from Singapore, can I apply Visa in Malaysia?" then the answer would be Yes you can apply the visa in malaysia and fly to any other country before flying to Country X.

Depending on the check in agent you might not be able to even leave KL

99.9% no problem. The only problem you might have is if your airline uses those auto kiosks that need to swipe/scan passport then will name mismatch. But then if that happens just go counter surely no problem one.

This is certainly not true of most countries. For example, Malaysian High comm in SG and UK no problem https://www.kln.gov.my/web/sgp_singapore/passport_renewal http://www.jimlondon.net/ppt_apply.html