The ratio of juice to honey completely depends upon a series of factors:
1) What is the alcohol tolerance of your yeast?
2) What percent of alcohol by volume do you intend to reach?
3) How much of the honey quality do you want compared to the fruit quality?
In terms of any fermentation, the differences are not that great compared to the similarities. I would not change that much compared to the successful fermentation you have already done. If you have your own system that works then stick with it, the only difference is the starting material.
If you are trying to get close to the maximum alcohol tolerance of the yeast you may need to add the honey in small batches during fermentation in order to prevent a stuck fermentation created by adding it all at once.
In terms of actual numbers, this is the art of fermentation and you need as the artist to decide. If you want it very floral with only a hint of fruit, use a lot of the watered-down honey. If you want a heavy fruit character and a high ABV percentage using strongly tolerant yeast (I love Lalvin EC-1118 for this), get the SG up there by just adding straight honey to the juice to close to 1.090-1.100 and then keep feeding it honey to get it back up to around 1.005 once it drops below 1.000 until you hit the amount that would max out your particular yeast.
To boil or not before fermenting, now that could start a war. Real honey is definitely not a "sterile" substance, but the likelihood of germinating the Clostridium botulinum spores typically found in honey during your fermentation is relatively low. I am definitely not a militant anti-boiler, but I tried boiling once and didn't like the mead I wound up with.
How well does the flavor come through? It's really hard to answer that over the internet without exact specifics. Honey is not by its nature uniform in flavor. With regards to infusing flavors, the ghost chili infusion then ferment would probably not be as potent as just fermenting with some chili in the bucket. Capsaicin is more soluble in alcohol than water.