2) Wrap your site in SSL, as by mid October, any non-SSL site will start being reported as suspicious by all major browsers.
3) Upgrade your WordPress version, to avoid being hacked.
4) Times to serve static resources (.css, .js, images) seem a bit long, so this may relate to your ethernet adapter being saturated (no likely) or your hosting company throttling bandwidth (very likely, especially in Asia).
Note: If your trying to serve content at highest speeds to Indonesia, then just lease a dedicated server in the US or Canada, from someone like OVH (cheap + fast).
Since Indonesia lives on top of the primary fiber connection, you'll only gain a few milliseconds of speed increase hosting in Singapore + have have to pay for much higher priced hosting to fix your connection speed problems.
Try OVH + see how your speed to Indonesia improves.