Is there a way...

[| Aloy |]

Not unless they go through them one at a time I believe. So, no. Why do you want them deleted anyway?

[Wanderer.]

Well unless someone has posted after you you can delete some yourself, but as Ocelot at Soul said it would probably take a while for anyone.
Also, I'm sorry to hear your quitting

[Nick]

That's possible, though it would really mess up any discussions that you were a part of.