Best answered elsewhere, but the short answer is:
1. GGL doesn't get you into any particular tier of lounge with QR that you wouldn't get from any Emerald status;
2. There is no dedicated F lounge operated by QR at T4 (the MH Flounge may be up and running) but the business lounge is equal to the CCR in my opinion.
3. At Doha, you'll have access to the Al Safwa.