Dear John, Nope it’s not ad free. Just like all Google services, this one too comes with ads… However, there’s no limit to the number of texts you can send in a day…

Regards to your second problem, I used to have a personal sms channel for me and my family with a lot of posts going out but never faced this problem. Maybe it’s a new restriction they’ve put because of the large number of channels out there. Just wait some time before sending out new texts… 🙂