install both 2008 and 2008 R2 developer edition

http://msdn.microsoft.com/en-us/library/ee210714%28v=sql.105%29.aspx

still confusing about this:

1. for SSIS I can use 2008 R2 version BIDs for developing both 2008 and 2008 R2 SSIS package and deploy them to 2008 and 2008 R2 production server respectively?

2. for Database engine and reporting service, I would install 2008 R2 side by side with 2008.
Since there is a default distance exist in the server (2008), when I install 2008 R2, do I have to create a named instance?

Thanks 

SQLFriend