I see that you have a few threads and blobs on the snowflake. I had these problems on one of my test pieces, see
this thread. The test piece was "hollow dodecahedron" from thingyverse, scaled down to half size. In the end I got better results after making the following changes to the slic3r settings:
Filament: decrease temperature on 2nd and subsequent layers to 200C.
Extruder 1: increase retraction to 4mm or 5mm. I'm currently experimenting with checking "wipe during retraction".
Skirt: increase loops to 2 and distance from piece to 15mm (to make sure the filament starts flowing properly, and make it less likely that unattached bits will get in the way)
Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod
Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].