Ipoh -> Senai airport -> Singapore - How to? Using Air Asia and Bus

I noticed that Google directed several queries about AirAsia and express buses to/from Singapore to this blog. So here's what I know, posted for posterity:

IPOH - SINGAPORE (BUSES):
Most of the large bus companies like SriMaju, TransNasional etc service the Ipoh - Singapore route. There is significant difference between buying the ticket in Malaysia and Singapore. At the time of posting, a 24 seat coach ticket is RM42 (buy in Ipoh) and S$37 (buy in Sgp). RM60 and S$47 respectively for the spacier 18 seater.

IPOH - JB (AIRASIA):
The flight frequency is 4 times a week (1, 3, 5, 7).
Inbound AK6562 (dep JHB 1330 arr IPH 1430)
Outbound AK6563 (dep IPH 1455 arr JHB 1555)

The cheapest fare is RM9.99 + 32.50 (admin fee!) = 42.49.
The most expensive fare that I have purchased is 119.99 + 32.50 = 152.49.
Obviously, if you're the first to book, you get the cheapest fare.

JB - SINGAPORE (BUSES):
Apart from taxis, there are 2 ways of getting from Senai to Singapore.
1. Senai -> 2nd Link CIQ -> Jurong Interchange
Take CW3 Causeway Express coach from Senai direct to Jurong Interchange via 2nd Link CIQ (RM8). From Jurong, you've got the MRT and a bus interchange.
CW3 buses are 2-3 hours apart (Big downside!).

2A. Senai -> JB Kotaraya -> Causeway CIQ -> Kranji MRT
Take the shuttle bus from Senai to Kotaraya (RM8). At Kotaraya, take CW1 Causeway Express (RM1) to Kranji MRT via causeway CIQ. From Kranji MRT, take the errr... MRT.
Senai shuttle bus is hourly.
CW1 buses are every 15-20 minutes apart.

2B. Senai -> JB Kotaraya -> Causeway CIQ -> Queens St (Bugis)
Take the shuttle bus from Senai to Kotaraya (RM8). At Kotaraya, take CW2Causeway Express (RM1) to Queens St via causeway CIQ. From Queen St, you have a bus interchange and the nearby Bugis MRT.
Senai shuttle bus is hourly.
CW2 buses are every 15-20 minutes apart.