Hope to some day see you back in the air hunting bombers again. 
This is highly unlikely. I miss my AH days a lot, though.
(Funny how everybody remembers me hunting bombers, when I actually spent more time flying them in the last 5-8 years of my AH life
)
Hope you and the family are doing well, God Bless.
We are doing reasonably well, though the wife being at home all the time because of the lockdowns really starts getting on my nerves
I always wondered if that was the case but has that actually been confirmed by HT in the past? The old timers swore up and down you had to let em warm up in the game so I adopted the habit myself.
I spend quite some time in AH over the years (yeah, I admit I was a no-life full time player), but I have never ever seen anybody mention something like that until your post. Wouldn't make much sense either, as engine temps are not even really modeled in AH, even WEP is strictly a time based mechanism. It's also very easy to confirm or dismiss it by a simple test (acceleration on the runway), which I would have done immediately if I had ever heard that claim.
You don't get much accomplished at 30k but that 20-22k sweet spot both delivers and makes you a nice target for intercept. Learning the balance while being able to defend yourself can be a game changer.
Yes!.
In the beginning I also tried to get the costly 29 as high as possible, but I quickly learned
most of the time that was simply a waste of time both for myself as for everyone going against you. In later years, the only times I would really get to really high altitudes (27k+) was when getting near Me 163 bases to force them into compression, something only a few pilots could cope with. According to my stats, less than 10% of my B-29 sorties were flown at 30k and above:
The main factor that determined my exact altitude when going above 20k was the wind layers. The missions I did below 15k were mostly anti shipping sorties, for the 29 makes a great sinker of carriers and battleships.
Also, maybe I can look up later how much combat I had at those different altitudes...
That is how you do it, from the waist. I've found no problems dealing with people who came in from below. If I can't hit them from one position, I switch to the other and usually took a wing. Then there is switching to one of the drones if you are in formation. You'll always get an angle on someone from below using that method. They can only line up on one of your aircraft, not all three. 
Absolutely! Switching between the drones is the key for engaging low altitude cons. You will find that there is no blind spot that way.
One word about loadout: I not only rarely flew with 100%, even rarer was using the 40x500lbs loadout. In most cases, I found it to be total overkill and a very inefficient way to fly the B-29.
I would use the 4x4k for sinking CVs (@25% fuel), milking town centers, some single factory targets. The 8x2k I used for hangar smashing, flattening towns for captures, attacking several factories (especially in the old central strats) or the new city. 12x1k and 20x500 were my 'light' loadouts for very distant, relocated strats or airfields & towns. 56x250 I used for the old city in the central starts with its rectangular city blocks. 80x100 was the lightest (old) city smashing loadout.
