I made 5 gal of this last year.
It's not bad, just takes a glass or two to get used to the flavor. To me it tastes like you'd think aloe would taste like.
I know Charlie P says it's the best mead he's ever had, but I got to tell you that effect only happens after about the 3rd glass...

I doubt you'd need a blow off tube, I didn't use one, but with 1 gal jugs there's not a lot of air space left.
I only used 1 yeast and no pectin enzyme.
The best advice I can give you to be patient...and don't sample it. Reason is there's only a gallon of it to start with. Taking hydrometer readings will greatly cut down the final volumne.