Guild Wars 2

I have a few questions regarding damage sigils:

1.Will 2 pistols with superior sigil of force give me +10% damage when using a kit?

2.Similarly, will 2 pistols with superior sigil of ghost slaying for example give me + 20% damage when killing ghosts.

3.Alternatively, will 1 pistol with superior sigil of force + 1 with superior sigil of ghost slaying give me +15% damage (against ghosts, +5% everything else)?

I was wondering about buying a load of very cheap pistols and wacking on the superior runes of … slaying, so I have + 20% damage options for different enemies when using kits.

Thanks!

i think people have reported 5% damage does not stack.
But things like 10% bleed, do.
Things with cooldowns.
Like, 30% vul on crit. share a cooldown with other such abilities.
So, if you run sigil of air. discharge on crit. 9s cooldown, sigil of earth bleed will not proc during that 9s.