It is possible to download the macupdates as combined update file. It's usually very large & is called a Combo update, and is installed offline, not over the internet. Apple - Downloads - Mac OS X Updates - Mac OS X 10.5.8 Combo Update

BTW I discovered I have the same problem. My OSX LW 5 also does not give the Facebook option. I have not yet heard back from the LW devs.

Re: startup disk: you will only see the startup options in Preferences -> Startup disk. Disk utility will only see drives.
So you do have two mac startup drives. I presume they are both OSX.

(I used to have a windows xp installation using bootcamp but the windows installation kept corrupting. And it was annoying having to reboot to get into windows. I now use a virtual windows via using Parallels. With Parallels I now have 2 x XP's and 2000. And can run all at same time in separate windows. Files drag & droppable between OSX & windows.)