How many do you recommend on the barrel hives?
The single bung hole entrance works fine and they can better protect themselves from robbing by only having to defend one entrance. For the winter I screwed in a bung, that had a 1" diameter hole in it, as an entrance reducer.
Do you think your hive was more accessible to bears because it was TB construction?
I don't think a TBH is any more accessible to bears than a Langstroth, but by nature of the design, the TBH combs are much more fragile and are destroyed by even a minor invasion. I had a Langstroth hive knocked of the roof of the garage by a bear, and other than a couple frame bars cracked and a deep supper coming about at the seams the hive was completely salvageable and survived.
Is this why you have moved to Warre type hives?
I have moved to Warres because I think the vertical TBH is easier for the bees to move across the combs, which is especially important up here with our long winters. The Warre layout more closely resembles that of a feral tree colony.
I really love that perfect half moon comb construction in the pic also.....lovely! Did most of your comb construction look like that or was that one an exceptional bar?
It was not a freak, all the fully drawn frames had a similar shape. For some reason, there was very little to no comb attaching to the barrel.
Would it be too hard to uncap that comb with a hot knife and use gravity to remove the honey and would it then be okay to replace the comb, or would this not be wise as the bees build natural comb to suit their current needs?
I can't answer that, never tried. I know most people with TBHs use the crush and strain method. But in his book, Warre mentions a wire cage that can be used when putting the Warre combs in an extractor. If you can salvage the combs and give them back to the bees, that is less resources they have to use to build comb.