The silkscreen layer position is useful to me, I'm working on a python script to check parts and I wasn't aware that silkscreen after copper was an issue, so one more thing to check for and complain about . The easy way to check hole size is to create the gerbers (file->export for production->gerber) and check the filename.drill file:
; NON-PLATED HOLES START AT T1
; THROUGH (PLATED) HOLES START AT T100
I don't remember what part this is (and the holes are odd) but the first is non plated through .039 in (probably a mounting hole) and the next is a small (likely too small unless it is a via) plated through hole. Changing them can be exciting in Inkscape because it changes what xml editor uses as units on some criteria I don't understand. If it has decided to use thousands of an inch, its fairly easy as it is diameter of the pad - 2 * stroke width. When it uses odd units, I usually copy / paste a pad of the correct size from another svg and then use the radius and stroke width from that (so the x/y coords don't change) to update the pads in xml editor.
To make the change in the files (which some of the folks here don't like doing, but I do ) you need to unzip the part's fzpz file and edit the fpz file (I use 7zip for this)
in the case of your part. This is an xml file that describes the part and the svg files (the format is described in the pat file format document). In this case you need to add a terminalId as I did on connector2 to all the rest:
<p svgId="connector1pin" layer="schematic"/>
<p svgId="connector2pin" layer="schematic" terminalId="connector2terminal"/>
The danger is that if you screw up the xml, there is currently a bug in Fritzing (which I hope to be able to fix once I finish the python script) that will cause Fritzing to hang due to a seg fault. When it does so you need to clear the user directories (which deletes all your sketches so you need to make sure you have backups first!) to recover from it as it has corrupted the parts database and not backed out due to the seg fault.
Yep, it doesn't appear to be an absolute requirement that parts start at 0, although the parts format document calls for it. As long as the pins are in sequence Fritzing looks to be happy. There is a problem if the pins aren't in sequence though as if there is a gap the descriptions will screw up (and be wrong when you hover over a pin in the views after the discontinuity). How I typically make parts (without parts editor) is documented here if you haven't seen it: