i) Does this product allow me to export a gedcom into a CSV format?
RootsMagic does not work with GEDCOM Files directly, i.e. it can import/export from/to GEDCOM, but can't edit GEDCOM files or export data directly from them. You would need to use a specific GEDCOM Utility for that, or a Family History software that stores its data in plain text GEDCOM files rather than one that uses a database; or you might be able to export the required information directly from a RootsMagic database using SQLite if you have an understanding of how to use SQLite software/utilities.
ii) Can I create a report showing person name, their mom's, and their dad's name?
Some standard reports list parents, but are you asking about a report for a group of people or for everyone in a database? There is a 'List' report which can be configured in a number of ways to do that.
iii) I like the idea of the duplicate merge function. Say we had this:
Person A with parents B and C
DupPerson A1 with parents D and E.
When I merge A and A1, does the new person let's call A1 now have parents BCDE?
Yes, both sets of parents would be retained and the individual would be listed under each set of parents. However, you would have to edit the nature of some of the family relationships after merging to differentiate between biological, step, adoptive relationships etc.