I feel somewhat embarrassed. I do not know much about Theraveda Buddhism and I hope I have not mischaracterised it. I have been told that the emphasis is quite different than in Mahayana and Vajrayana. I have also been told that the apparent contradictions due to that difference are not in fact contradictions.
The way Vajrayana is taught and practiced it may seem that I am free to do whatever I want to do. I am certainly free to think whatever I want to. (I'm struggling for an analogy here because it is so foreign to western thought.) It's like I can go out and drive like a maniac and wreck all the cars I want to if that's my desire. No one will call it 'bad.' But I have to work as a paramedic every single day as my practice. And, unless I want to extend my practice further, (and thus the analogy) I have to pay all of my fines, damages and jail time. But the paramedic thing is mandatory. (very rough analogy)
There are many approaches (and I'm not familiar with any but the one) but I think I can safely say that the one thing in common is 'mindfulness.' I think every approach is centered on that.
I'm free to not study the Dharma if I like as well but as soon as I choose to pick up a book I am faced with endless admonitions against negative behaviors with reminders of the inevitable consequences of even the slightest downfall. Like all the Buddha's teachings the doctrine is free of condemnations but chock full of what works and what won't.
Some think that Tantra is a license to licentiousness but it's not. It's hard to explain. Once you begin the path every downfall makes life difficult while you're practicing and if you stop practice it gets even worse even if you act well. There is no turning back and that's as it should be.
I don't think of it so much as restrictive as it is conditioning. I had suffered from clinical depression for many years, and much of my thinking had to be re-routed. The dharma is quite similar to a treatment for depression called "cognitive behavioral therapy." After a while it's not a struggle and it becomes natural.
I know I'm not going to be perfect and I'm willing to take the personal consequences of my actions. But I'm also aware that every sin I commit is the spiritual equivalent of sticking my hand in a fire. It's not something I often find worthwhile.