To answer several at once...
My daily weight loss has varied but my average loss seems to be stable at about 0.3 kg/day according to my Google Docs food diary.
I'm not sure I'd go as far as to recommend a 100% veggie low carb diet to a non-vegetarian though. Swapping out some of the animal products may help but, particularly during induction, the veggie plan can be a challenge. It certainly makes eating out anywhere quite difficult (I usually just end up having olives and a salad). My carnivore housemate had a much easier time of induction than I did.
Regarding linseed - I get the H&B brown linseed at a fraction of the price of the golden one. Probably not
as healthy but it beats the wheat bran I was using as a fibre additive previously and I get plenty of omega 3 oil as a bonus.
At least one source seems to suggest there's little difference:
http://www.goldenflax.com/flaxseed-faq.html#goldvsbrown
Regarding the Sainsbury's drinks - I'm fortunate enough not to be sensitive to aspartame or sucralose but drink sucralose by preference because it tastes better. I find aspartame has a very obvious "diet" taste whereas sucralose drinks taste as good as the full sugar versions.
Unfortunately several people seem to have stalls with various kinds of sweetener and I guess you've just got to find what types and quantities work best for you.
Sadly my own fatal stall food seems to be cheese which is a real shame as it's my favourite.