Hi Roger, not sure if I understand you correctly ... but it sounds a little as if you are combinging the basic setup at the start of the sit with later techniques.
If I read you right ... the four stages are just preparatory to help you focus in. So focussing on world, body, breath formations, breath at the tip of the nose, should just take a few minutes - maybe as little as one breath each. Then count the breaths up to eight. After that, just keep the focus on breath at the nose. Then if you have dullness or mind wandering just notice this and return attention to the breath at the nose. Keep doing it. And keep on doing it! At the end of the sit, count your breaths backwards from eight and go through the four stage process in reverse, then you can rise from the cuhsion. Maintain your concentration for a little longer if you can, as you go about your daily life.
The techniques for following and connecting the breath are more advanced, and I wouldn't do those until you have strong concentration. Instead, if you are having difficultly keeping the attention on the breath at the tip of the nose, expand your attention to include more of the breath body (e.g. the rising and falling of the toso, or the sensations in the throat and lungs).
Over multiple sits, as you practice attention on the tip of the nose, dullness will reduce and gross distractions will reduce. Once you can keep your attention in place consistenly, then you can start considering other exercises, as noted for each stage. But get strong concentration first, before trying to deconstruct the breath or any of the other techniques.
Hope this helps. Ask away if it is not clear, or if I have misinterpreted what you are saying.
