I've of course forgot most of my questions by now ;-)

First of all, let me give you an overview

While porting I found a number of issues, I marked them all with the word 
PENDING. Searching for that word should help you find the issues. I added a 
comment telling what the issue was.

Many of the issues are with the plugin expecting local files. It was decided 
to extend this to URL's in KIPI. Currently I just convert the URL to a local 
file, but at least a warning should be issued, and in long term the plugins 
should handle real URLS.

The cdarchiving plugin did seems to expect that all files for archiving was 
located in one directory. This is not true with say KimDaBa. I fixed it a 
number of places, but there are still some issues, e.g. in cdarchiving.cpp it 
calls AddFolderTreeToK3bXMLProjectFile, previously with a directory.

KIPI doesn't have a way to tell the plugins which directory a set of images is 
in (as they might not be in a common directory), so this needs to be reworked 
(It's your code, right, so I hope you will continue feeling responsible for 
it even after it has moved to KIPI ;-)
You did have CVS access to kde.org, right?

Finally, I've seen some plugins asking for "collection", what is that?

Cheers
Jesper

PS: Are you on the kde-imaging@kde.org, if not let me urge you to join us 
there.