Shield is one of those shows that would have worked much better with less episodes. After Cap2 things really picked up. They sound like they learn from their mistakes, season 2 could be something.
As for this, I'm hearing more of a "it's promising" vibe, rather than outright praise, interesting.
It will definitely hurt. Unlike kids movies, where people watching the DVD rips probably weren't gonna see in cinemas, TMNT has an older fanbase that would have. An audience that will probably stick with the torrents and streams rather than pay for the exact movie on a bigger screen.
Everyone I know who was interested in TMNT has already downloaded or streamed it. By the time it comes out in the UK I imagine the BluRay rip will be out by then too.