10 days modified

Do you mean that you don't want to stay in Paris more than two nights, or there isn't time to stay in Paris more than two nights on his route? If it's your first trip, you might want to reconsider that, as two nights really only gives you one day. If you plan to see Versailles, you need at least 4 nights IMO, preferably 5. RS itineraries tend to be too fast-paced for me, but they work for others, I'm sure. But, I would see what you want to see, not what RS says are the sightseeing priorities in France. High speed trains connect a lot of different regions, making it feasible to see Paris and Southern France, for instance, in the same 10 day vacation (BTW, does 10 include arrival and departure days, or is it 10 touring?). With 10 days, I would personally pick two regions, and I would pick the two regions you are most interested in, as long as they are easily connected. But I'm a slow traveler...if you prefer faster paced vacations, you may want to continue with RS itinerary.

What Beccas says, x2.

I think it is logistically feasible to visit 3 destinations in 10 days if they are reasonably proximate, such as Paris, Normandy, and the Loire. It will be a sprint though. 4 destinations, or 3 that are not logistically efficient, is a stretch without another day or two.

normandy and Loire are roughly West of Paris ; Beaune/ Burgundy is east. Not very efficient to do Burgundy with a western area... go around paris? So That would suggest either Normandy and Loire OR Burgundy and Champagne or possibly Alsace