you can change page name from details popup, but on first look it's a good point that it could also be changed from main window like menu item title. We'll consider implementing this.
Regarding trash can, it's also good point and also will be considered.
As for your last question. With page manager, .scpages file is introduced. It's functionality will be explained in details in upcoming documentation for pagemanager. Here is how it works currently:
By default, all files with supported extensions (can be configured in config file with 'site.default_pages' variable) in site root directory are considered as pages. If you want to add specific pages from subdirectory you need to create .scpages file in your site root and state each file in new line.
In next release (2.4.3) that should be released today or tomorrow we added possibility to state entire directory (eg. subdir/) and also possibility you asked for, to filter files by extension (eg. subdir/*.php)
There is also possibility to exclude specific file (or dir as from next release) by prefixing it with
!. So if you want to include all files from subdir except contact.html and also want to exclude about.html page from site root dir, your .scpages file should look something like this:
If you, for example, want to include all files from subdir except .php files, you should be able to do it like this:
Pay attention how entries are ordered. You should always first include a subdirectory and than exclude specific files from it. Otherwise it won't work.