Two puzzling print behaviors w/ Hictop Prusa i3

[saucepicious]

So the first issue I am having trouble with is fairly innocuous (it doesn't completely ruin prints but is very annoying nonetheless). At seemingly random points in a print, the printer will suddenly re-zero the x or y axis and then continue on its merry way, leaving one or two ruined layers in its wake. It only seems to happen when I try to use a layer height smaller than the default 0.3 mm. Also, the issue is inconsistent from one print to another, even if it's the same g-code and same part that it is running, which suggests that Slic3r may not be to blame here.

The second issue is much more serious: again, at seemingly random, inconsistent points in the print, the print head will suddenly stop moving while executing a perimeter, then suddenly and violently retract the filament until it completely pops out of the extruder assembly. After this, it goes through the rest of the print as if nothing happened.

I have experienced the first issue from time to time with previous prints and models, but both issues seem to be very prevalent with the latest model I've been trying to print. Attached you will find the STL file and a screenshot in Slic3r.pawn_mk2.stl <- That's the STL file apparently.
Screenshot (4).jpg