Nice videos
1. Use Net Radiant, it has an option to cover all new brushes with caulk by default, shows in grid view which part will be cut off when clipping and more. Net Radiant = GTK Radiant + fixes, updates, new features.
2. To change floor into full box, you should flip on Z-axis on larger grid size and move to right height, select both, clone, rotate around X, clone, rotate around Z. Done.
3. You should always use the largest grid size on which you can do whatever you need to do.
2nd vid:
4. To select only brushes, you can show/hide entities with Alt+2
5. To make hallway, you should make only 1 wall, clip edges, then flip it to opposite side, clone both, rotate and resize.
6. Don't use hollow D: It creates a mess that you have to clean up. There are easier and faster ways.
7. If you somehow get what u did with hollow and 4 clips, then instead of clipping 8 times to match with the room brushes, you should select all 4 brushes, go to vertex mode, select from top/side view all outer verteces on 1 end and drag them where they need to be, same for other end.
8. Instead of calculating how wide the door should be, your simple hallway could have been aligned to grid better
9. You didn't caulk door faces that are not seen.
