Is this kind of self-massage and energy practice safe?

For most healthy adults, yes — the techniques are gentle, self-administered, and meant to be done at a comfortable, non-forceful level. All pressure should stay mild and comfortable; if anything hurts, ease off or stop.

That said, this material is educational, not medical advice. If you have a heart condition, high blood pressure, diabetes, or any kidney or reproductive-system condition, or you're simply unsure, check with a doctor before starting. Results vary from person to person, and the practice isn't a substitute for professional care.