The knockback sets have some damage, but definitely not enough to be solo viable. After all, the primary focus is doing knockback.
The build is incredibly useful to shore up weaknesses in teams similar to how controllers work -- if not better. After all, knockback is just a spammable hold. When enemies are flying around willy nilly, they can't fight back except for popping off maybe one power every few seconds.
Since this build has no healing, it takes Vengeance for the inevitable scenarios in which enemies do decide to attack back and someone faceplants, and also for the extra LOTG slotting. The Resuscitator temp power is useful in this situation.
I have had the occasional issue with teaming due to people's misconceptions about knockback being some ancient, insufferable evil, but the teams that do let me stick around either find it hilarious, legitimately helpful, or both.
Did get reported for griefing and cussed out once, so this build may not be for the faint of heart.