I sure do. I don't know how well the spices will take but I say give it a try! And let me know how it goes I would love to hear and possibly try it myself.
I don't enjoy dry meads myself though I do make a few at request for customers. I have often back sweetened. Warm water and however much honey I think needed. I have back sweetened a batch more than once at different stages as well.
As far as stirring goes I don't suggest that you do it vigorously if at all. I have never heard of stirring it save for right when you make it. I have never stirred any of mine. If it is putting off gasses then I say let it go. When making mine. I only warm the water to aid in the honey...
It could greatly be that your air gap is four or five gallons of air. The gas has a lot of room to fill especially when opened. It looks fairly normal except usually you would see gas bubbles forming. I highly suggest buying the ingredients to make your six gallons much closer to full or a...
Though I am new to this website I am not new to mead brewing. I started over seven years ago and brew nearly 200 gallons every 6 months or so. It sounds to me like your yeasties will be just fine. An air gap is a good thing. In my five gallon carboys I leave a good 6 to 10 inch gap. If you don't...