I've been trying to configure a basic editing app for a big Esri customer using the Web AppBuilder that needs to be hosted on ArcGIS Online. This was sold to the customer by Esri as major benefit to their solution. I've configured this using the geocode widget and edit widget and initially was impressed by how straightforward it was.
However, after showing this to the customer and playing some more with the app, I've found the following:
Basically, the Web AppBuilder is a good start, but I'm far from convinced that it is suitable for production use yet with all these issues and considering this really is a very basic app we are looking to configure. Yes - we can download the template and hack about with it and then host it ourselves, but then it's not OOB or COTS then is it!
These are all valid points/issues. It is great that you have reported at least two of them to support but until users like you report all issues/enhancement requests, this things are less likely to get resolved quicker. Most products begin this way covering many of the basics and failing in areas that seem so logical to use that they would have tested using this or that scenario, but the truth is they don't initially. Keep providing feedback to support.
I came across your posting because I was under the impression that the search widget didn't support entering in a coordinate pair as you state in item number 6 in your post. Nothing about the configuration of the widget would indicated that, but if you do enter in a coordinate pair of the coordinate system displayed in the app it will find and provide the ability to zoom to the result.
Note that Robert provides a nice enhanced locator widget that provides a lot of options, but my customer use case is hosting WAB on AGOL and thus no custom widgets. There is a posting titled "Web AppBuilder Search/Geocoder widget" on ideas.esri.com if you're interested.