Thanks for your comments Richard,
I managed to find some recommendations in the COADE's Seminar Notes (page 2-53). It is advised that sustained +wind is checked against allowable, but not thermal +wind.
I assume your case 5. should have been L2-L1. Then case 6 is sus+wind and you confirmed the above (page 2-53).
I have updated my cases and they are as follows:
1. (HGR)
2. (HGR)
3. W+D1+T1+P1+F1
4. W+D1+T1+P1+F1+WIN1
5. W+P1+F1(SUS)
6. L3-L5(EXP)
7. L4-L3(OCC)-wind
8. L7+L5(OCC)-wind+sus.
(9. L7+L6(OCC)-wind+exp.)
If the stresses in cases 8. and 6. are acceptable, can we conclude that case 4. will be acceptable regarding stresses and ignore case 9. (even it shows excessive stresses)?