Warming honey to dissolve into water is alright by me, but any excessive steam, foam or boiling action is losing delicate aromatics within the hone and changing the overall profile of the honey in question..
I prefer taking some of the wine and warming it on the stove - no water needed; use the "Warm"/"Low" setting on the oven - and dissolve the honey into that, as soon as the honey is dissolved, i remove it all from the heat and allow it to cool closer to room temp with occasional stirring before adding it back to the bulk of the wine
Sweetening with honey will most-times cause a haze of sorts, but that just means it bulk ages for a bit longer before bottling.. No big deal with meads, as they benefit from longer aging anyways.