Install to internal HDD from USB drive

[Moltke]

One application I (and many others too I assume), would really appreciate would be some way to automatically record all installed applications and automatically re-install them after upgrading

  Well, a couple of months ago I reinstalled LL after having broken it up  : I used Aptik to reinstall all of the apps except those ones I'd installed via a .deb file. I really like aptik; very easy to use and really lighweight  http://www.teejeetech.in/p/aptik.html

Also, systemback has the option to create an .iso image from your current install so that might just be what you're asking for. Haven't tried myself though but the option's there.