Too many variables

1. Do you prefer F lounge access (then credit to a different program) or higher upgrade chances (then credit to MPC) - given you fly ARN-HKG (hopefully in J) quite a bit, BAEC could be an option for you which could get you OWE.
2. Status match to CX Silver max is what I have heard - maybe CX Gold under very special circumstances
3. Too many credit cards - my view on good "all-rounder" is SCB Asiamiles card or BEA Flyerworld card

The only issue with these is that you're locked into the increasing useless Asia Miles programme. I tend to prefer more flexible points currencies such as Citi ThankYou, HSBC RC or Amex MR since these transfer to other (for HK) relevant miles currencies such as Avios or SQ Krisflyer Miles.

that is true.
but citibank earn rates not that good unless you are on prestige (which has been devalued)
hsbc vs is a good card - BUT only if you choose the appropriate Reward of your choice

my everyday card is the citi prestige, but i play the diff cards for diff promos (eg hsbc set for home so groceries on it), however the prestige did not have the avios 1.3x promo this year i think so that is a negative

Agree with all of this, but for someone new to HK it could make sense to pick up the Citi PremierMiles for the welcome bonus points + $4 / mile for the first six months. This could also be complemented by the Citi Rewards with $3 / mile at supermarkets and broadband/mobile bills.

Citi Prestige probably doesn't make sense with the new annual fee unless you can squeeze out a lot of value from the 4th Night Free benefit. OP mentioned he'll be travelling a lot so it's possible he can cover work travel expenses with this card and get 25% back on his statement.

We've put both of our household HSBC VS to Overseas Spend since 50% of our spend is overseas, but this will vary depending on spending patterns of course.

Sad (but possibly) accurate reflection of the times to see Asia Miles dismissed in passing as increasingly useless. Is it only a matter of time before Asia Miles availability deteriorates to the point that even the FF programs of the mainland carriers to whom you can transfer CC points via BOCOM, DBS, etc start to seem like a viable alternative? (China Eastern anyone?)

I try to stick to Cathay (+Dragon) for any short/medium haul flying due to their dominance in the HK market -- thankfully they can be redeemed with Avios even though availability has been cut significantly since 22 July.

For long haul I am increasingly finding myself redeeming on other airlines -- either CX partners such as QR, or the likes of SQ which is a transfer partner with Citi, HSBC and Amex.

Based on the wiki, Amex Plat earns 1 mile / $3.75 on overseas spend:

How is this calculated? Is it:

3 MR / $1 (= 1 mile / $5) for Overseas spend + 1 MR / $1 from the Turbo programme (up to $160k)?

It's not quite clear on the Amex website.

Selection is based on HKID, not the card.
You selected 5x for one card and it applies to all cards under your name.

In fact one does not need HKID at all to do banking in Hong Kong. Passport and address proof are the only required documents. You can have transactional accounts, debit cards, credit cards and investment accounts (stock trading etc) without HKID. The very few things that you cannot have without HKID are Octopus-related products (Citi Octopus cobrand) and Citi UnionPay credit card.

1. CX does not have a fixed procedure for matches, but they do match on case-by-case basis. As far as I know however, you can get maximum MP Silver (which still gives you lounge access when flying CX). You would probably need to show past record on CX flights and few future bookings with them in addition to status proofs with a competing carrier.

4. HSBC is a nightmare. Citibank and SC are nice both for banking and mileage earning credit cards. Other banks to consider are Da Hsing (for BAEC Avios) and Fubon (for spending in Japan, Korea and Taiwan).

That may technically be the case, but I was flat out refused by HSBC when trying to open an account shortly after arriving in HK some 27 months ago, despite having my passport, the little white slip that acts as a temporary HKID, company letter etc.

My HR department informed me that Citibank (as far as they knew) is the only bank that will open accounts for expats who only have the temporary HKID slip. Sure enough Citibank helped me out, and opened a Citigold account despite me not meeting any sort of deposit requirement.

I opened an HSBC account with only my passport and short term lease agreement the day I arrived in HK, about 4 years ago. But sounds like things may have changed.

I think back then you could walk into an HSBC branch and open a business banking account -- for context HSBC have basically stopped opening new biz accounts at this stage...

Does your company do their corporate banking with Citi?

I remember many years ago that there was a promo where you got Citigold if you had your salary auto-credited and it was in excess of something like $60k a month. I didn't qualify at the time so got a normal account. I asked later about upgrading and was asked to deposit $2m or something ridiculous. lol

No they were (I've since moved companies) with another bank.

Re. Citigold, it was definitely an introductory offer based on salary auto-credit -- only valid for 1 year, and I've since been downgraded!