1. PDF EXPORT:
- It would be nice if you could decide what you want to export as PDF - for example only the plan in 2D without the inventory list.

Please use the page setup dialog to choose what you want to print and/or export to PDF.

- And it would be very nice if the plan wouldn't appear with such bold lines.

I reduced the line thickness in prints in the upcoming version 4.0.

2. Rotate:
3. Edit Room

The advanced plan editing plugin should help you (see user guide here).