Communication is key here.
Yes you are correct. MP and cover do not block LOS.
A quick, hey I am going to MP behind cover and intend to get out of sight from so and so and it will take me at least an action to pop up to shoot, and agreement from the other player does.
The best (and fastest) games I have ever played were when the rules we rarely if ever discussed.
Throughout the entire game pretty much all that was said was:
Looks close enough to me.
If you shoot at MR, I will return fire at MR.
I think this is what should happen, it makes sense, agree?
I think it should be -2 for cover here agree?
I think Walkers do not get a penalty, right?
Shoot, I forgot envoromental role, here is the role now.
I think I will need to take a leadership roll now since he is down to half of his wounds.
I can go on and on.
BTW, thanks Dave, Josh, Dodger, Archer and Phil for the great games we have played over the years.