I just want to inform you that I solved - by myself - both problems. Nobody helped me.
Regards to row Style, I realized that I need 2 styles. There isn’t such example in vaadin documentation to specify this.
[size=3]
[color=#000000]
And second, I was able to implement the checkbox in a grid thanks to one video about vaadin grid.
This also should be explained and showed more simple in vaadin documentation.