I have a ticket for May with a CHC-SYD-HKG routing. CHC-SYD with QF (but operated by JQ) and transferring same day to SYD-HKG with CX on same e-ticket under CX stock. Will this itinerary enable me to do online check-in on cx.com and print my own boarding passes using a hotel's printer? If so, will I only be able to print the BP for SYD-HKG or will it also allow me to print the BP for CHC-SYD? I will not be checking-in any bags.

In this case, do not attempt to do online check-in for your SYD-HKG flight at cathaypacific.com. Doing so will prevent JQ in CHC from issuing your SYD-HKG CX boarding pass when you arrive at the JQ counter in CHC (if JQ and CX has interline check-in capabilities).

Instead, do online check-in with JQ for your CHC-SYD flight. When you do this, JQ may be able to "attempt" interline check-in in the background for your CX flight and at the same time issue your CX SYD-HKG boarding pass.

As a general rule, when travelling on a ticket with different airlines, always do online check-in only with the first airline you will be flying.

Note: If JQ does not have online check-in and/or interline through check-in with CX, you might be able to check-in at cathaypacific.com and receive only your SYD-HKG boarding pass. However, if you have not yet checked in for the JQ sector, CX's system might see the e-ticket coupon for the CHC-SYD JQ sector marked as "UNUSED" and refuse to check you in for the SYD-HKG CX sector. Once you have checked in with JQ (either online or counter), then you will be able to check-in for the CX flight (since the CHC-SYD JQ sector would be marked as "CKIN" or "checked-in").

In my experience with CX-AA combo, AA can print my boarding pass after OLCIing subsequent CX FLTs but not vice versa. I would not be able to print my CX BPs no matter before or after checking-in for AA FLTs, though. I think for CX, a E-TKT coupon with a segment operated by another carrier will simply be marked as "CTRL" (control), from the time the E-TKT was issued until several hours after flying, in which case the coupon status will switch to "USED." I think the "OPEN" (not "UNUSED") -> "CKIN" -> "USED" sequence can only be seen on CX / KA FLTs.