Hi there,
Thank you for purchasing my eBook!
In Punch there are 2 important concepts related with printing.
1 - The space where you develop your project is "The workspace". You will draw your property inside the workspace, but they don't have the same dimensions. You can see more information in the page 152 of the eBook.
For this reason, the A3 page is smaller than the workspace. Of course, check if the A3 title block is scaled.
2 - In order to print, Punch collects all the info in the plan, so if you have any object (even a dot) in any corner, Punch will consider it as part of the plan and will print it => in this case, this dot will modify all the page sizes and scales. You can see more tips, definitions, and images regarding this concept starting on page 264 of the eBook.
Regarding your questions:
Originally Posted by: Ant B
1 Is there a better way?
If you are interested, in my store,
my Advanced Collection includes scaled 2d and 3D tile blocks, so you can set and move the exact paper size for plans and elevations
Originally Posted by: Ant B
2 Is 1:100 the largest scale? This is somewhat inhibiting for a large site for a whole site plan.
Yes, it is. But you can print to 50% (for example) to fit the desired paper size.
Originally Posted by: Ant B
3 To select the entire drawing & reposition into the best space within the A3, there doesn’t seem to be a select and drag option?
Select All => Move => Set the desired distances (Page 214 of the eBook)
Originally Posted by: Ant B
4 Snap doesn’t appear to work using the dimension or offset tool
Not sure what do you mean? Can you share an image?
Hope this helps.