
What to Expect When Removing The Baseboard?
Cheaper thin baseboard will likely break into pieces no matter how careful one can be, most notably ones that were finger joint manufactured. How to find out what type you have? By looking closely at the profile you're likely to make out the manufacturing method.
Leave The Baseboard Alone

Our preference has always been shoe molding especially if the existing baseboard has a low profile. Example on the left shows 3/4" quarter round overwhelming the colonial style baseboard.
Other thoughts to consider; Don't be surprised if the perimeter of the floor is not flat once you install the base after the floor is completed. Perhaps you don't like the appearance of any trim on the baseboard.
Chances may be good once the base is being installed humps and valleys are seen under the base, or gapping. For larger gapping the only recourse is either to install base or shoe or have the one doing the work "scribe to fit the base" to the undulations in the subfloor.