A) Yes. The following are some of the steps; I have taken in doing so:

1) Definitely take a back up of the whole project(s) by exporting the project
as a .dsx file

2) See that you are using the same parent folder for the new version also for
your old jobs using the hard-coded file path to work.

3) After installing the new version import the old project(s) and you have to
compile them all again. You can use ‘Compile All’ tool for this.

4) Make sure that all your DB DSN’s are created with the same name as old one’s.
This step is for moving DS from one machine to another.

5) In case if you are just upgrading your DB from Oracle 8i to Oracle 9i there
is tool on DS CD that can do this for you.

6) Do not stop the 6.0 server before the upgrade, version 7.0

Install process collects project information during the upgrade. There is NO
rework (recompilation of existing jobs/routines) needed after the upgrade.