Love that the gunsaber works underwater, but it feels really similar to a spear with just ammunition abilities. Might be worth changing up a few skills to differentiate it, but I think it works fine for the most part.
Also could it be possible to have the sigils on the non-equipped weapon set trigger on weapon swap for the gunsaber? I think a lack of an ability to add runes can negatively impact some swap traits. This isn't the biggest of deals as this doesn't happen for holo, but thought it worth a suggestion.