SSIS Packages with SQL Server Express 2008 R2
I think you need to be clearer on your exact intended setup. That will allow for a better reading of those two linked questions. I would guess that those two links are actually irrelevant. SQL Server Express comes with a stripped down version of SSIS (or can be installed via the Tools or Advanced install), according to Link #2. But yet your question regards "creat[ing] packages for use between the Standard edition of SQL Server and the Express instance of SQL Server" which implies that you have Standard Edition. If that is the case, then you can create and run packages from the BIDS and SSIS that came with Standard Edition, and connect to Express Edition instances to transfer data back and forth. Documentation that says "SQL Server Express 2008 R2 doesn't support SSIS" is not saying that Express cannot be connected to (unless, of course, your testing indicates otherwise).

EDIT:
Testing indicated that this did indeed work; creating an SSIS package from BIDS that came with Standard Edition, and running it from Standard Edition, was able to connect to Express Edition. The only caveat is that, as noted by @Gareth in a comment below, "certain functionality won't work, for example History Cleanup, as it's not supported by Express Edition".