Because the overall first flight on your itinerary is marketed by United, and the itinerary touches the US, UA’s baggage policies will apply on the entire flight.

The answer is no. :-) There are many reasons for this, but the simplest is that international flights have positive passenger bag matching. You can’t voluntarily separate yourself from your luggage.

As far as the fees, you’re running into one of the gray areas here. United treats an upgrade as applying to the underlying fare, which is why it’s quoting you the luggage fee for business class (two pieces) and then telling you that the fee for a third piece would be waived as a courtesy for your 1K status if you checked in with UA. In my experience, your operating airline will not see the business class allowance, but instead will see the economy allowance.

That said, as I read it, your flight is actually operated by Brussels, so I’d expect that you’d get your second bag for free due to your *A status. You can (and probably should) bring your receipt and see if you can get the second bag fee waived, if they try to charge it in the first place. If you can’t get it waived, you can see if UA will refund it. They should, honestly, since the DOT requires that they disclose luggage fees on the receipt and your receipt says $0.

UA does a terrible job of disclosing fare families, but I don’t think this matters in this case because UA’s policies will prevail. I can tell you that you’re not in Basic because your W fare was upgradeable; Basic is EuroWings’ version of Basic Economy and would not be upgradeable.

I flew Brussels and saw the same thing you did. My carry-on wasn’t weighed, but YMMV.

Naah. That’s boilerplate. Germanwings doesn’t even exist anymore. UA is required to advise you of the operating carrier at the time of ticketing. It looks to me like it’s Brussels, operating the flight on behalf of EuroWings.

The MSC would be UA, which is another reason that they would use UA’s policies.

Well, again, that first carrier is UA. However, if it were not, UA would be required to provide at least as much free baggage as the first marketing carrier would. The idea is that the DOT is trying to keep people from being blindsided by baggage fees on the return trip (or even a continuing leg after a stopover). However, there’s no restriction that would prevent them from providing more free luggage, which is exactly what they’d do — you’d still get your 1K allowance even if they were following someone else’s policy.

You’d be wasting your time. The phone agents have no clue.

this. UA waivers (more accurately) for premiers will not apply. So weight limit will be 50 lbs, and you’ll get 1 extra 50 lb. bag for being *G.

unless things have changed, CX can check your bags through if on the same ticket, but they won’t be able to check you into the UA flight or give UA BPs. Last time I tried this (BKK-HKG on CX, HKG-EWR on UA), I was told the systems they use for check in are incompatible. I really pushed, since My connection was 1 hour, 10 minutes (no longer legal, thankfully). There were about 2 dozen of us connecting to the EWR or ORD flight at HKG - which both leave around d the same time. It didn’t help that we were late arriving into HKG.

Other issues aside (yes, there were), upon landing at HKG, you need to go to the transfer desk to check in (or if you arrive before the check in cutoff, which we did not due to CX delay, you should be able to OLCI in UA app - should actually be able to do this once your Cx BP is marked as boarded, so using CXwifi if it exists). Note if you have checked bags, even if checked through, you’ll still likely need to stop at the transfer desk to validate the bag transfer on the UA side.

While HKG is definitely an efficient enough airport, due to the check in issues, (on CX or Hong King Airlines), Id personally recommend at least 2 hours for a connection - though not sure what MCT is these days.