Deleting an old Sythe account/posts

So, I had a Sythe account from 2013, I like the account but there are a lot of posts that I'd like to delete (exposes personal info) so I created a new account to start a few services. The new account is this.

I would have loved to have used my old 2013 account but I didn't want to bring attention to posts that are sharing my old Skype username and other things.

Is there any way to have old posts deleted or an old account deleted all together?

The sad thing is I will miss my 2013 joined date.

Any help on this matter would be awesome.

P.s. I am aware of the 2 account rules and have not interacted between them. My old 2013 account I log into occasionally.

Happy to share the username of my other account in DM (to a mod), don't want to share publicly.

EDIT: I would also like to change my username, I'm over the Sailing theme

Thanks!