Hi, YES, I am a WORDPRESS NINJA ! ;-) I also have extensive knowledge in Information security and pentesting so understand hacking stuff pretty well! Well, it's not possible to GUARANTEE 100% security, I can assure you that I will check everything including DB, Files etc. for any backdoors or possible outdated scripts/plugins which might have been used to hack!
Also, I might recommend you to change your Hosting login passwords etc. to further tighten up the security! :)
P.S.: You forgot to attach the TEXT LOG?
Would love to discuss further.
Shall we?