In the first example, more so than the kerning, there are a couple of issues that stand out right away. The first is the negative spaces (the eyes), especially in the A, are very small. The A is difficult to make out as an A because that spot is almost entirely filled in. The eye of the R is also really small. With the i you only want the bar at the top and bottom when it's actually a capital i when it's by itself, at the beginning of a sentence, etc.
I think your second example is much better. I think it's important when lettering to not use your regular handwriting or handwriting at all. Make shapes, not letters.
Personally, I don't have the time and patience to hand draw the letters so I just use a font. ._.
SFX I always hand draw though. Hand drawn SFX look better very close to 100% of the time. I won't say 100% since there are always exceptions, but...
It isn't really a rule or anything, but typically hand drawn bubbles, like SFX, will look better than ones that are perfect circles/ovals. I find they feel more integrated with the artwork.
CSP makes it super easy to make bubbles since you can use a vector layer for them. I use the vector layers for bubbles and backgrounds since you can use the eraser to automatically erase the extra lines with just one click!
