OMG ))
That's quite a text ))
I am not a literary translator and I'm completely unfamiliar with the terms.
Ok, here's my attempt:

1.
Ayvazovsky was never repainting the sky in his paintings, it was always painted just once. It makes the sky in his paintings look lighter and adds transparency, clouds seem to merge with the colourful canvas. A completely different technique was used by Ayvazovsky when we was painting water. The waves were usually very well detailed, while the first layer of paint was drying off a little, a new layer, depicting all the smallest details, the lace of the sea foam, was applied to the still viscous first layer. Painting the patches of light on the water surface in pastose (?) was the final touch.

2.
The ground and stones were painted by Ayvazovsky with rough bristle brushes. It is possible that he was cutting them in a special way to make the brush end leave furrows on the paint layer. The paint in these places is usually applied thoroughly. Ayvazovsky was glazing the ground, as a rule. The glaze (darker) tone, getting into the furrows, was bringing a peculiar liveliness of the colours and lines, and more reality to the depicted form.