The first link points to the blog then to jetsetter which requires a login. I can offer advice on SG. Spent 20 years there.
SG is actually the more 'liberal' country in that region. So not too much culture shock. No tips required for restaurants/bars/taxis. There are a few historical places/off the beaten paths that I'd recommend in SG, ie Chinatown (which is vastly different from the ones here in the US), Little India, Arab Street , Geylang Serai Malay Village etc. All within walking distance or MRT (subway). Take advantage of the bus/MRT system. Taxis are everywhere as well.
Sentosa is over-rated. All major malls are over-rated. Newton Circus (not the clown/elephant type) is over-rated. Raffles hotel on the border of being over-rated, even the Singapore Sling cocktail. Jurong bird park is actually quite decent. Avoid Night Safari. Fort Canning is worth visiting, so is the National Museum.
Food is a must. For a place that serve all local cuisines with the touch of authenticity, I'd recommend lunch buffet at Straits Kitchen in Grand Hyatt (Singapore Restaurants: Straits Kitchen, Grand Hyatt Singapore, Singapore
). Reason is you get to sample what local cuisines are before actually hitting the streets. Bourdain went there, we went there and you know it's good when the locals go there. Reservations STRONGLY recommended.
Visit the new F1 track, which is the street track that circumvents the Supreme court, cricket club, Anderson bridge, War Memorial park, Victoria concert hall, Esplanade theatre, etc. If there's one thing I miss about SG, is the road. Years of living there, I don't recall seeing one pot-hole ever. Notice I mentioned 'new' F1 track. SG used to host F1 back in the late 60s. That old F1 track is located north of the island, which unfortunately is a bit of a hassle to visit. Street track as well.
Yes you can chew gum. You can even bring gum in. In fact, you can wave a stick of gum at the customs officers and nothing will happen. Buying gum at 7-11 is a different story, ie none are sold.
SG is a country that has a national language of Malay, business language/first language as English and ethnic language as second language. It bans pornography yet legalizes prostitution. It has zero national debt and yet you wonder if it's because they tax 250% to 300% on cars and in additional one needs to bid for Certificate of Entitlement in order to have the "right" to own/drive a car. Pollution of any kind is next to none. Most Singaporeans don't really delve too much into politics/religion. Don't be shocked by line jumping and shoving in a crowded area. Leave the notion of FCFS at home for now.
I haven't been to Malaysia and Thailand for a long time. My last recollection of TH is Phuket and the Phi Phi Islands (before the Tsunami hit). SG tends to be more urbanized while in MY and TH you still can catch the slower pace of life in the suburbs and rural areas. For TH, please at least try a local curry dish. You'd be surprised they taste very different from the ones offered here.
As for hotels in SG, I can recommend
1. InterContinental Singapore (extremely convenient for MRT)
2. SwissOtel The Stamford (extremely convenient for MRT)
3. Fullerton Singapore (not so convenient but a wow factor)
4. Marina Mandarin (somewhat convenient)
5. Ritz Carlton (somewhat convenient)
If you have other choices, post them here and I can review/advice.
Hope these help!