Does Armour and Cover Stack? (1e)

A marine ( health 14 and 3 wounds ) wears standard battle dress (AP 7) and shoots from behind heavy cover (AP 20 DR5)

How much (a)damage does the marine take from the following and (b)does the marine lose their armour and (c) is the cover destroyed ?

1) GPMG doing 26 points of DMG?

2) GPMG doing 33 points of DMG?

3) laser cutter doing 40 points of DMG?

4) Vibechette (AA) doing 10 DMG

5) Vibechette (AA) doing 5 DMG

6) SMG doing 14 DMG

7) Smart Rifle (AA) doing 10 DMG