Hi Nittany,
Well, I think losing 8 or 9 pounds in a week and a half means your Induction is working very well indeed - well done! You won't lose large amounts daily. What happens is that the body just needs a little while to recover from such a large loss.
All you need to do is carry on with the plan, and soon some more weight will go.
Have you measured yourself? It is also very common for people to lose inches before pounds. This happens because many of us don't eat sufficient protein before low carbing, so once we do get enough, our muscles increase a little, and muscle weighs more than fat.
If ketosis is making your breath smell (as it often does) the only tried and true way to improve things is to dilute the odour by drinking lots and lots of water. When i'm heavily in ketosis I notice the first few glasses of water for the day taste a bit odd, so I add a squeeze of lemon juice.
My heartburn pretty much improved when I started LC so can't really help you there, On the odd occasion I do have a problem (usually from taking NSAIDs) I take ranitidine tablets.
Many people find they still lose well while drinking their coffee. But if you think there is a problem with your weight loss, why not drop it and see if it helps?
As for the aspartame, the same thing applies. Dr Atkins also advises against using it for as its safety has not been proven. personally I much prefer the taste of Splenda anyway.
HTH
Rosebud