Just so it's clear, the changes to TBWinRE in WinRE (when you have updated the installed WinRE) only affect that instance when changed/disabled by a Windows update/upgrade. If you have created TBWinRE boot media (CD, UFD, etc.) or are booting from a TBWinRE WIM it wouldn't affect those (though you would probably want to eventually update to the newer WinRE version). So, the boot media is the same as IFL in that regard -- it won't change after being created unless you change it.
There are restrictions on the trial versions (some features are missing or not supported, for example), but you can create customized boot media versions.
The IFL boot media supports booting UEFI with Secure Boot. You don't need to do anything specific to enable it. Do try it on the system, though, and make sure it boots okay in case any normal boot/layout settings may need adjusted.http://www.terabyteunlimited.com/kb/article.php?id=572http://www.terabyteunlimited.com/kb/article.php?id=317
The "restore disc" mentioned in the manual usually refers to the disc that would be created if you save your backup image directly to CD/DVD/BD. The first disc is the "restore disc" and can be booted. There are separate options for the restore disc and the boot media when you create customized boot media.