Andreas,
As to your first question, there doesn't seem to be anything from Sparx. However, given that they only recently created the DOORS add-in, this subject is clearly in their view these days.
Perhaps a suggestion to Sparx is in order, coupled with a thread in the Suggestions and Requests section. I'll leave it to you to start it if you agree.
Regarding the SysML question... I doubt they (the EA add-ins for DOORS and SysML) are linked at all, being separate products. You could install either one without the other, so I suspect they are both aimed at the 'core' UML functionality of EA. I could be wrong here - perhaps the DOORS add-in stereotypes and tags elements for SysML. In that case nothing would be evident unless the SysML add-in were installed, but the results would be valid UML regardless.
I do think this is a good idea, though. It bears following up with Sparx.
Finally, I don't think the DOORS tool is two way. It seems to only read DOORS, at least in its initial version. There was a thread posted on this subject recently, so a search will get you the answer.
David
