My first attempt at chashu

I have a couple questions.

1. I feel like some of it's a little on the fatty side. Is it normal to have some variation, or should I have trimmed some fat down?

2. I feel like the slices are a bit large in diameter. If I wanted them smaller should I have thinned out the cut of pork belly; again maybe I should have trimmed some fat? Or should I have cut it shorter?

3. Also some of it seems to want to unroll after slicing, is there a trick to getting it to keep together?

Thanks y'all!