This should work, I've just tested that. The configs are stored in the registry. THe user config is storted ujder the path HKEY_CURRENT_USER/SOFTWARE/PDFPrint and the application config is stored under HKEY_LOCAL_MACHINE/SOFTWARE/WOW6432Node/PDFPrint.
You can use the NO... keys in both, the user and the app config.
NoTrayIcon=1 disables the try icon
NoOnlineConverter=1 disables the online converter
NoOnlinePdfTools=1 disables the online pdf tools
NoShellContextMenuExtension=1 disables shell extension
NoPDF24MailInterface=1 disables the PDF24 mail interface
NoFax=1 disables fax
NoCloudPrint=1 disables cloud print
All the values above are DWORDs.
If you see some buttons in the GUI after you have configured not to show that buttons, please make a screenshot and send it to forum@pdf24.org and then I'll look a bit deeper into the code to check that that.