You should have absolutely no problem with language in Singapore. Almost everyone speaks fluent English. Other than taxi drivers, most people you will encounter in HKG speak passable English. (However, about 50% of them start the conversation with the phrase, "Copy watch, mister?" )

There are scads of excellent hotels in SIN and HKG, as well as BKK. The major chains (Hilton, Hyatt, Starwood, etc.) all have properties in these cities plus there are some outstanding 5* properties in each city, if you want to pay the tariff. All the hotel staff you will encounter at these properties, from chambermaids to concierges, speak English, most fluently.

Don't sweat travelling to Asia. It is mostly populated by friendly, helpful beautiful people. And to top it off you are flying F on CX, one of the two best transpacific carriers, the other being SQ.