Yes pcb view (apologies, I’m so used to which is which I don’t even think about it). The way I remove the translates is usually manual ungrouping in Inkscape. Deepungroup (which ungroups recursively) does not remove the translates only shift-cntrl-g in Inkscape does as far as I know (and in some cases even that doesn’t remove them, notably polygons). If I can’t delete a translate any other way, I select the item and record its x/y height/width values from the top tool bar, then in xml editor I select the translate and blank out the translate value and set it. This remove the transform but also moves (and possibly rescales) the item so its coords in the tool bar are now incorrect. I then set the values that the translate originally had back in to the tool bar which usually will move and if necessary rescale the item without using a transform (as long as the item isn’t a member of a group, if it is in a group Inkscape will usually use a transform to change it). As noted this doesn’t work for polygons (but isn’t vital either, polygons with transforms are usually not a problem for Fritzing). Its a big pain in the ass, but the only way I know to get rid of the transforms if they are causing trouble. If someone knows of a better way I would love to hear it.
absolutely correct, for large numbers of changes that is what I do using regular expression replacement in the text editor. Any way that works and you are comfortable with is fine.
It isn’t necessary, the part will work fine (all other things being equal) with the current scale. It is suggested that this scale be used for parts in the part file format document because it makes 1px be 1thou in. If all the parts are scaled the same then the parameters in xml editor (in this case calculating the size of the drill holes) is easier because we know stroke-width should be 20 and hole size is pad diameter - (2 * stroke-width). While it is always possible to do the math above, it is much easier to be able to only change the radius to a new (probably known such as 29 for a 0.038 hole) value. You will find lots of parts that are not scaled properly but work fine. I’d like to see them all translated to the correct scaling for ease of modification (others may not agree).
By and large it looks fine, however I think one connector is slightly misaligned. From the gerber drill file:
INCH
T100C0.038000
%
T100
X019217Y014222
X020222Y014222
X018222Y014222
We see the first X coord of the holes X019217 is 5 thou (I think!) smaller than the others at X018222 and X020222 when they should all be the same. In practice it may not make any difference but I prefer precise (as you have probably discovered 
). The why is more of a problem. With the tool bar set to inches all the pads look fine (and thus probably are fine). The problem looks to be connector1pin, its y coord in px is somewhat smaller than the rest which is what I expect is causing the change in the gerber. That would indicate it is likely round off error in Inkscape and can probably be ignored.
I tend to agree with Old_Grey on this one, but it is really the decision of the part maker, and your argument is likely correct, the real pcb is likely to connect via wires to the sensor (which is sometimes mounted on a servo and thus moves). That said the silkscreen doesn’t hurt anything and if someone does mount it on a board they will get some idea of what other parts the sensor may interfere with… Your choice! You are learning well although as we said there is a lot to learn …
Peter