There's only a certain amount of emphasis to go around. The more things you italicize, the less important each italicized word seems, and then when something's really important it doesn't stand out. It's like swearing---if I swear every time I spill a glass of water, then it loses its effect and when I drop a hammer on my toe there is nothing I can think of that will express the strength of my feelings.

In comics, the difference in weight between bold and standard is much less than in typical fonts. I think it works well in comics but here it makes me read things out of order in a distracting way.