I loaded it into so recent RealThunder edition.
It is dumping a ton of warnings about missing plane references (not sure, but it seems you picked them from different parts of the models), but it loaded it fine, required an overall recompute and it looks good. I exported it and as far as I see it looks ok in Cura5.
My Cura Visuals are ugly like hell as my laptops 3D capabilities are below what the normal display engine requires. Therefor I cannot really see rendered layer lines, but only the fallback rendering, which shows straight lines with the curves coming from the bottom. I have a displayless MacBookPro 2018/2019, which hopefully will be my next printer support system. This annoys me for years. 
I must say the model itself looks great and I am impressed by the result. Maybe change the names of pad/pockets and sketches to make stuff more readable. Especially when you return in a few years and what to change something (software developer speaking). 
You also used a lot external geometry, which is a very bad ides. if you change stuff like size of the inner fillet, everything below will probably break due to random renaming the references. If you want to use these functions and e.g. put sketches on faces and stuff. That usage is very dangerous with the official version. This is a 10+ year old bug and still not fixed in the official branch. In the real thunder edition 99% of those issues are gone.
In fact since I used the broken branch for years, I still use datum planes and offsets a lot. Mainly because I name them properly and have a surface I can easily find, when I need to a pad or a pocket later on. Something like “DP_HingeTop” is a clear information and you know what you get when adding a sketch to that.
If you want to use the “old” version you need to model around the center point and use datum planes. It is stupid but external geometry and sketching on pads should not be done with the official edition. Their tutorials usually show that, but this is because the examples are not that complex and they never change something in the past of the model. The real thunder version gets frequently updates.
If you want to see what I mean, open the “PartDesignExample.FcSTD” file from the “start”-workbench. This is the official example file, which does what you do: referencing.
Look how the top looks like a castle with the recessed trench and the shoot nodges. Double click the “Sketch” named sketch. Add a circle to the tower at the right. Just put it over the other and with a smaller diameter. You have now changed the past of the work flow tree. This expect a new hole was added through the entire tower, but the model will be inside out, because FreeCAD renamed all references as the circle is a new line and the pocket creates new surfaces and edges.
The castle wall looks different, because the wall top pocket is missing. It is now at the bottom of the model and other features may or may not have been changed, depending on the version. The model is now completely broken and requires massive work to fix all the references. This can even happen, when you change a measurement in spreadsheet, as e.g. if a pocket gets change from “through all” to “4mm”. The inner bottom of the prior hole is now a face and an edge. FreeCAD will rename these in and everything afterwards is broken.
If you do the same test with the real thunder edition, you just get a hole through the tower. I use this simple test to check if the build contains the bugfix or not.
Use this one to get all the features and the bugfixes of the original version plus the reference issue fixed. It appears a little later, but has all the good stuff you want.
