Starhub should have an option for delivery usually, but since u picked Nex it might have been blanked out.
Galaxy Gear Watch is only available from October onwards, if you preorderd they will give you a $100 off voucher.
Starhub should have stock as long as your pre-ordered and booked an appointment. For M1 it's first come first serve.
Only Singtel limited the accessories pack to the Value plans and above, Starhub and M1 give to all plans.
Samsung has drop off points all around Singapore which will take 2-3 days, but their Marina Square outlet will be able to process for you on the spot usually. Samsung doesn't do 1 for 1 refurbished set like Apple, usually they'll repair it.