Ask a developer to use a stored procedure and majority will look at you as if you are mad.
Not really in my experience. Some are better than others, but it's not hard to include a few simple test cases for the edge scenarios in a proc, as well as spot checks against known test data.
ORM is not newbie friendly. Stop giving it to them.
Application development in general is not friendly to UNSUPERVISED newbies but they can produce useful work with ORMs in say a triad with a senior and or mid level dev.
Depending on your application much required functionality is little used or is very straightforward, maybe for admin, config etc - often 80% of a project code base in my experience. No performance tuning is required and to implement such using procs is essentially premature optimisation. The 20% that is heavily used or uses intensive processing - sure, write the procs. If you get more usage later unexpectedly for a particular area and it causes problems - write the procs. No big deal.