OK - I see your Fitday -
As far as calories burned - I wouldn't trip too much over logging couch time unless you are trying to be able to report less of it in the future?
I do like Fitday for the reporting - and that might be fun to be able to look back at later.
on the aerobics and the walking - it is so important to exercise along with watching what you eat. If you really want an accurate count of how many calories you are burning, I recommend a heart rate monitor. That being said - I also think when you are just starting out, if you watch your calories and move, which you are already doing, you don't need to be really hardcore about the EXACT numbers. Later - when you get really close to goal might be a whole different story.
You didn't ask about opinions on what you ate - but can I suggest adding some veggies?
It's a great way to get lots more volume in without adding a bunch of calories.
You are on the right track - asking questions is good! You'll get lots of advice from the chicks (and dudes) here.