it would be very useful to be able to give the page a php extension, rather than php.htm which currently happens.
Only your first page would need renaming to .php after export. All other pages can be given the .php extension in Web Properties>>Page>>Pagefile Name: These will be exported correctly as .php and not break your links from the starting page etc.

Click image for larger version.  Name: name-php-file.png  Views: 240  Size: 10.0 KB  ID: 64541

Secondly, it would also be useful to have an option to be able to add code to the page header
Please try to search the forums to answers to questions like this one - it has been discussed man many times.

Adding code to the head section of your page is done by creating a placeholder which you name: <HEAD>
Your code is then added via Web Properties>>Placeholder>>Replace with HTML Code