Maybe the solution from the WeTab feaseable:
http://wetab.mobi/en/developers/
Search for "HowTo – Get Root Access on WeTab OS".

Even Android devices can be returned to non-Jailbreak-mode.

Their solution is obviously a compromise:
- alllow everybody to become root - this is everything a developer dreams for. This is the most cheap way to spread developers devices to everyone interested in
- do not restrict hardware support at all (see below)
- restrict software support to those devices, that have not openend dev mode (root mode)

There are (at least) two risks:
1) Devs brick the device (accidentally or on purpose) and manage to return them to the manufacturer without having to pay a single penny. This would be the case, if the device is bricked so hardely, that it would be impossible or too expensive to find out, why the device is bricked.
2) Devs destroy the hardware with their developed software (e.g. overclocking)

The first could be solved by reanimating the device by reflashing the device as it has been done when it was produced (using JTAG, spelling casts, praying...). It would be thinkable to ask for a small obulus for such a service. This would never cover the expenses for the manufacturer, but at least it would recover some of it.

The latter has to be evaluated more closely: Is it more cost effective to just exchange this device at no charge or to evaluate the reason for the defect? That depends on how often will (defective) software actually kill the hardware? Or maybe it is even cost effective to kill 5 devices, until the darn clocking registers in the bootloader have the correct values :-)

This i doubt. I see this more in black or white. Eighter open the device (no risk - no fun) or use the "ecosystem" and pay for your needs to someone. I do not belive, that the no-risk-no-fun-people are that many, that it would be efficient to differenciate rules in applications or the OS itself to allow or forbid actions regarding the kernel or single apps or boot-skripts.

Please note, that this is IMHO :-)
@Sksteeps: Thanks for such inspiring questions. Mer will undoubtably benefit from all of the discussion!