Hi,
Regarding the fact that you can't select a custom order status in your mass action, that's a bug that we fixed with HikaShop 3.5.0 :
www.hikashop.com/support/documentation/5...ashop-changelog.html
The mass action filter and action "order status" where looking into the category table instead of the orderstatus table. We've now changed that to use the new table we've added in HikaShop 3.0.0.
So I suppose you're using an old version of HikaShop and if you update your HikaShop, you'll be able to select your order status.
Regarding the delay, you'll want something like that for that filter:
order_modified < {time}-432000