Should work but 1 is unnecessary.
The log backups are independent of the initial full backup or differentials.
There are a series of log backups and fulls/differentials. You pick a full + differential to restore then apply all the following logs.
If you are planning to leave the system offline while this is set up there is no need - depending on how you install it (I tend to code it manually rather than use any inbuilt tools but I think the 2008 version will copy the full backup and logs for you).
If you want to do a cold backup then I would take a full and restore that then close the system and take a diffential and restore that - depending on your system it might mean a lot less down time / critical admin work.
Try it on a small test system to make sure your architecture works.
You might have problems scheduling the log shipping on top of a manual restore of a backup depending on how you do it. I can remember having to play around with some flags to tell the system it was synchronised in older versions.