Thanks MAS 
1step - I'm glad you have had your ops now, and hopefully recovering well from them. It's always scary waiting for results especially when they change what they say - the same thing happened to me and it did throw me a bit. But as everyone says it sounds as if they are being thorough. I used to think of the lymph nodes as a sort of filter to stop rubbish (i.e. cancer cells) getting to the rest of your body, and they generally do a pretty good job.
And when it has spread to the nodes they will offer you chemo as an extra back up - try not to think in terms of 'I've got to have chemo, so it must be bad' it's a scary idea, but if they offer it, its because they think they can do a good job of zapping the cancer with it.
There's several people going through chemo at the moment on here - so I'm sure they'll be able to give you lots of tips and support (mine was 3 years ago, so I'm probably out of touch
)
gracie - they will monitor your heart very regularly on herceptin, and test before they start to give a base level, they are interested more in changes to your base level rather what that level actually is 