1. The banding - a known problem with the Quintrix F tube... most common are slight bars at the sides (mine has a very slight LH bar)... the centre is certainly something which you shouldn't have to put up with.
2. Patches - I must say that my set is now patch free. Some users from NZ mentioned probs with Philips sets so it looks like they aren't looking after you Southern Hemisphere folks. Even though your speaker is shielded it really shouldn't sit on top of the TV... you said yourself that it gets worse when you do this.
3. The NTSC issue - there is no Double lines option simply because it would be identical to the Pixel+ mode for NTSC as explained by Zacabeb in an earlier thread.
4. Geometry- can be set-up separately for 100Hz and Pixel+ - the TV switches modes as you go through the menus. Pay special attention to the "slope correction" I have managed to get good geometry in all modes on my set.
With the banding, I suggest you get the set swapped. As for the patches, assuming Philips are now calibrating properly for the Southern Hemisphere, they should disappear after a few weeks of internal degaussing [set off at mains every night] (mine did).
Hope it all works out for you as when it does, you'll love this TV!