Some questions about los and sizes

I read in rules “32mm= normal, 40mm= large, 60+=huge”

  1. What category of size have 30mm models?
  2. What category of size have 50mm models?
  3. How work rule “Models on the shooter’s own side do not give cover as they are working together”?
    3a) Does it work only for normal-sized models?
    3b) Does it work only for calcuted covers or for los-block too?
    3c) Does large-sized models gives cover?
  4. LoS is defined for attack action, but is used in many other situations. Is it correct, to use this definition to measure the work of auras and other properties?

I always round down numbers. Eg 50 is NOT 60 so the smaller number is used.
The cover works as "you can’t use dogmeat (Or other teammate) as cover because they would be a “human” shield.

But 50 isn’t 40. And (fo 30 )we can’t use smalller then 32. Does this cover rule uses for huge models? “Normal-sized models which are not friendly to the shooting model also give cover” how it works for large-sized models?

Sorry to clarify the 50/40 rules works like this. (All sizes are just to make things easier)
Dogmeat is 10
Human is 20
Mutant is 30
Power armour is 25.
Because the power armour is at least 20 but NOT 30 the smaller size counts.
Think of it like targets.
As for the cover rules I’ll have to reread the rule book as it’s been a while since I’ve read it.

Sorry, I don’t understand. Do you propose to come up with homerules?

According to the Rules of Play on page 17, it’s based on the size of the base, not the height. For some reason the size of some of the bases are off by a mm or 2. Most 60 mm bases are actually 59, but they’ll count as 60.
The standard sized model is on a 32mm base: Dogmeat, Nate, Nora, other human sized ofigures. They’re Normal
Power Armor and most Super Mutants are on 40mm bases, so they’re Large.
50mm based models aren’t 60, so they’re Large.
60mm or larger are Huge. On page 17 of the Rules of Play, it also says that models on bases 60mm in diameter or wider block LOS for smaller models. So Frank would block the LOS of a Radscorpion.

But 50mm base aren’t 40… ok. I see cover/losblock ruled only for huge and normal-size units, but has no rule for large-sized units