I expect to start a short-term assignment in Doha during January. My employer will unfortunately only provide economy class flights. I will be travelling from London to Doha and have Oneworld (BA) Sapphire status. Since I will need to take quite a lot of luggage with me on my first trip and having never flown QR, I would especially value this forum's advice regarding the luggage situation on QR:

1. I believe the standard QR luggage allowance from LHR-DOH in Economy is 30kg. I assume I can check-in multiple bags within this weight limit?

2. From the Oneworld website it says that Sapphire members should receive an additional 15kg luggage allowance. So I assume I should have no problems checking-in up to 45kg of hold luggage?

3. Does QR strictly enforce the standard Economy hand luggage limit (7kg)? Does this also apply for Oneworld frequent fliers? How strict are they?

4. If there was a reasonable price to upgrade my ticket from Economy to Business I would consider paying the difference. Does QR ever offer reasonably priced paid-for upgrades when space is available in the same way that other airlines (e.g. BA) do? Would this potentially impact the flexibility of the return ticket (e.g. would a fully flexible Y ticket upgraded to J impact the flexibility of the return Y sector)?

Any thoughts or advice would be very welcome!