I would agree since these classes are probably the last classes of the "dex-based" group that needs to put their stats into Dexterity, then Agi, then Vit, and then the remaining into strength. They'll never have the carrying capacity of strength based classes, and their other dex classes (sniper and stalker) and magic classes already received the boost.
It makes no sense why Gunslinger shouldn't have it, especially since their HP is still relatively low, meaning they need to put most of their stats into vitality.
As for the clown and gypsy weapons, I feel like the boost isn't enough, (as they'll do roughly only 3.5k per hit on frigg users), so perhaps adding the increase limit boost instead of more damage will help with survivability.
[EDIT]: If the new clown and gypsy weapons get increase weight limit, add them to the soaring bow for both classes too, since switching to the bow would make a person over 90% weight.