Here is one useful piece I got through further reading of documentation:
"DB2 Connect™ Personal Edition: This product is a superset of the IBM Data Server Client"
- IBM DB2 9.7 for Linux, UNIX and Windows Information Center

This means that the IBM Data Server Client I installed was not necessary, and the answer to all my questions on whether I need to configure that IBM Data Server Client *before* or *after* installing DB2 Connect is not before or after, but instead, that is, I need to install DB2 Connect *instead* of IBM Data Server Client .

So now I just have to follow the DB2 Connect installation instructions. I did find the Try/Buy version:
IBM - DB2 Connect Personal Edition V9 Trial Licenses
So all I have to do now is install DB2 Connect, download latest fixpack, and register this license? Or are there any other tricks I need to know?