About importing MS Office documents:
Spreadsheets work fine, functions are not imported (simple +/-,... should work).
Presentations work very bad.
Word Documents work rather well in most cases, but no pictures are imported. This filter is based on wv2.
Exporting to .doc and .xls is not implemented. But you can export to rtf and csv.
With the upcoming KOffice 1.4 I would recommend importing all your data with OpenOffice 2.0 and saving them in the Open Document format. Most of the KOffice 1.4 components (KWord, KSpread, KPresenter,...) support this format. If you have to do this only once with your "old" data, then it should be ok. With OOo 2.0 and KOffice 1.4 it is generally a good idea to use OOo for converting from and to MS Office.
Regards,