Some of it is true, but then I would rather prefer to share the dressing room with International players rather than just playing Indian domestic games. There is so much to learn. People like Yusuf and Jadeja were able to showcase their talent because of the IPL. Yusuf had himself said in an interview that if he hadn't played under Warne, he would have never been good enough to play international games. And one big positive I see with overseas captain is that there are not biased, they want to pick the best side and get the best out of the players. Also, think of people like Rajat Bhatia, LR Shukla, Stuart Binny, Karn Sharma, Ashish Reddy, Mohit Sharma,Iqbal Abdulla, Kamran Khan, etc. IPL has made a massive difference for them. There are many players who have got repeated opportunities in IPL. There are a few negatives, but there are more positives to look at from a players point of view.
I'm looking at it from the point of view of grooming players as well as building an Indian team. It's rather hard to build an optimal Indian team from the IPL, because so many Indian players miss as at least half the matches their teams play. Already Rishi Dhawan has been benched for one game, after being the leading FC wicket-taker and also a leading run-scorer in T20s. While one can say overseas captains are not biased, they are also not confident in the Indian player base, which is why an excessive rotation of players takes place, while average or unproven or over-the-hill overseas players are in prominent positions. Let's not forget, Watson's international career was revived by the IPL and David Miller's, kickstarted by it.
My solution to this is to reduce the squad size, and more importantly, reduce the number of overseas players in each squad, and eventually, the playing XI. That way, the best players can make each side, then eventually learn from the stars, and grow. That's how all the other T20 (and other domestic) leagues across the world work. They breed their own talent, instead of scouting abroad, and buying at princely prices, then hoarding, the way IPL teams do. Fair, that will make the IPL a lot less lucrative, but it will also make it a lot more productive in creating India players.
Shrikanth Wagh is a really good bowler and capable of bowling 135+ regularly, I have seen him bowl, I think there are several bowlers like him who need good mentoring. There are many bowlers who are raw, but have serious potential, I have not seen any special effort from the BCCI to manage or groom pace bowlers or pace bowling all rounders even though we need them the most. Some of the names apart from the ones you gave would be Jasprit Bumrah, Sandeep Sharma, Awana, Dhawal Kulkarni, Anureet Singh, Rahul Shukla and Veer Pratap Singh.
Indeed. However, it's too much to ask of Shrikant Wagh, who's a lot slower than we'd expect a pace bowler to be, to lead the attack and get bagfuls of wickets alone. The likes of Steyn, Morkel, Johnson (current IPL figures notwithstanding), Finn, Umar Gul, bowl fast and can take plenty of wickets to make a difference alone. Wagh, on the other hand, needs to be part of a combined unit to be effective- including one defensive bowler who's also a batsman, and one bowler who can bowl genuinely fast. Jaspreet, Rahul Shukla, Anureet and VP Singh are new, and need more seasons to shape up. All the other blokes are merely seam/swing bowlers, who will struggle because of their lack of pace, on not-so-helpful wickets. They're hardly capable of running through batting sides alone. Sandeep Sharma, supposedly bowling with even less swing than before, but not bowling any faster, will make a good T20/ODI specialist bowler, for now.