When I added manipulators in Blender they had preselect highlighting, as do buttons. That is an OK convention for UI widgets. This got lost in porting to 2.5, and I would always agree on bringing that back.
Selection of faces/edges/vertices/bones/etc in Blender is not “click and guess” but IMHO one of the best working features of Blender - in which we beat other programs still. In 3d views you just don’t have singular selection possible (small elements, overlapping elements, etc). For that reason Blender has a heuristics that includes the distance to mouse, and cycles based on this distance (including on Z depth). If this doesn’t work well, I would call that a bug to solve - and have developers make it more predictable on single/2nd clicks…
Next to that, one of the key design concepts in Blender is to follow the non-modal “Select -> Operate” paradigm. Selection is the state, operations the user’s toolbox that should be fast accessible. In other programs (like Maya) they use the “Operator -> Select” approach; that means you first set the tool (translate) and then apply that on selections. In such a modal UI a preselect is more understandable to use.
I’ve been blessed to work with great developers and Ui designers in the past decade, and for sure will welcome them in the team. It’s not very uncommon from new developers to require to first investigate a bit how things work, what the designs are, how we intended to have things work, and what’s been agreed on together in the long history of Blender.
More over; for a student who’s getting paid for 2 months of GSoC, we can expect to be even more flexible and stick to agreed topics first. Students were hired to be working for us (the developers mostly) to help out! That students also have their own ideas and aspirations is great, but there’s nothing better than a successful GSoC project to get such things smoothly happen. 