Hi Piwoslaw!
I have used grille block only in winter time, but yes, it is a good idea.
Lighter oil. 10W40 is on test by now, because I used this after the renovation' but the engine was very thirsty for this, so I changed for 15W40. About 1000km ago I changed back for 10w. If he (his name is Bordeaux based on the body colour) don't sip from this oil, I will try lighter one.
Wheelskirt. Hm, I see that you have this kind of body parts on your Peugeot. How did you fixed them? I think, they are removable and not fixed with screwes. Do you have pictures of yours at short range?
pulse & glide
What (/who) are they? The only thing that came to my mind is: Bonnie & Clyde
Thanks,
Doni