Point or sharp edge increased the electric field strength( top point of arc rod used on the top of tall buildings for lightening stroke, keeps clouds of same charge away) and electric field(charge)distribution would not be uniform. Round up of edge or corner could increased the uniformity of charge distribution of, and could make the electric field, more uniform....

Yes, this would reduce the hot spots and enhance the distribution of the electric field. As a result, the breakdown voltage will increase.

At high frequency specifically, rounding the edges of a conductor greatly reduces the skin effect and increases current density uniformity throughout the cross sectional area of the conductor.

Yes, it will increase the field uniformity by reducing the peak field.

Hi Roland

Have a nice time !

According to wikipedia: "The lightening rod effect , or the sharp point effect is a physical phenomenon explaining the influence of a sharp metal object on the surrounding electric field. The typical applications of this phenomenon are the lightning rods". Further, since the field lines are closer together near a sharp point on a conductor, the field is stronger near the sharp tip than on the flat part of the conductor.

In conclusion, the answer to your question is naturally yes. The more the surface of a conductor is rounded the more the electric field is uniform.

Please take a look to this interesting video (in french) attached below and also the following link (also in French) :

https://fr.wikipedia.org/wiki/Effet_de_pointe

Rounding the edge of the electrode plate where the high electric field strength happened might help as discussed in theoretical basis. However, there are more things to consider to solve this one where arcing can happen at this point.