I've said a few times that the "Umpire Calls" rule should be scrapped, IMO if a ball is touching the stumps even for 10% or even clipping it (the current rule is for more than 50%) then it should be out but I guess ICC willingly leaving some scope for human error in umpiring despite tech is available there to use.
Yeah, a huge number of matches in the domestic circuit could create a financial burden but we can't deny the fact that it does help players immensely. I think they will use this according to grouping (relegation). Also, I'm in favor of using full fledge technical/technique analysis for players so that BCCI can identify and tackle their weaknesses at a domestic level, shouldn't cost more than $10-15 Million per season for satisfactory results.
I don't think that if the ball is just clipping the stumps, the batsmen should be given out. It will put the batsmen in a disadvantage. I would go with the 50% rule. But then the loophole needs to go away. The umpire should not be given the leeway to decide whether the batsmen is out or not. That decision should be made by the DRS. And on the second topic, if it is just $10-15 million, then I am fine with it. And it is going to generate additional jobs as well. So there is no excuse for the BCCI to not to implement DRS in domestic circuit.