1. Yes, the Beckett/AGon/CC trade was mainly a salary dump because they wanted to clear out some malcontents from the clubhouse and start over. That's not really up for debate. I think they got ok value considering how much the Dodgers took on. Gonzalez provided decent value his first 3 years and CC for 2, but overall they ended up eating some bad contract years (especially with Beckett who was never the same).
2. I don't believe the Betts deal was a "salary dump." They included Price to dump his salary, sure. The Betts portion wasn't to clear $27M off the books, it was to get future value for losing Betts in less than 12 months.