Essentially yes. If we are being pedantic, “chipload” is the chip thickness at 50% stepover or more, while “chip thickness” is the actual max thickness of the chip after taking chip thinning into account (confused yet ? 
)
Yes, but no one hardly ever speaks about chip “length” because it’s mostly irrelevant to the quality of the cut.
Exactly.
That would be my guess about what happened, possibly combined with a feedrate that was a tad too slow. I went back and checked some of my settings back when I was doing tests cuts in acrylic using a 1/8" O-flute:
At that time I ended up using 16k RPM, 54ipm. But that was a stiffer 1/8" than your 1/16" endmill.
Maybe 40-45ipm @18K would improve the cut in your case (but don’t go breakings bits just to prove me wrong 