Right, you don't want to look like Arnold or anything. You already have a six-pack, you just have to strip away fat for it to show. You have to change your muscle:fat ratio. This is done through resistance training.
Props to you for spelling 'lose' correctly but you lose a point for using the word 'tummy'. That word won't fly here.
No. You have to increase overall muscle mass by doing full body resistance training (which would include abs) and increasing cardio. You are still under the mentality of 'spot reduction'. Working abs has NOTHING to do with shedding fat in that area.
Maybe yes, maybe no. If you increase cardio and start lifting, you may not have to reduce calories at all. The fat concentrated in your ahem, 'belly' will go, but it requires patience. You know... first to come on, last to go.
What plan? I don't see a plan yet. All you have said is cardio and ab work.
You're really going to have to be more specific in your goal. What type of cardio? What type of resistance training? What are you eating? etc. Actually, the good news is that newbies CAN increase muscle and shed fat at the same time by maintaining protein levels (.8-1.0g/lb) and burning more calories than you are taking in. But, you don't really have a plan yet and I'm sure some others will layout some plans for you. Be prepared for darts, but others will suggest some very good weight training routines for beginners.
I did Body-For-Life about three years ago which has its share of criticisms in and around usenet. I had a huge pot belly, but time and patience pays off. Before and after pics are here:
www.knossos.org/training/
Good luck!
- Osc