I can't say I read all of them, but from the browsing I did, the last one seems vastly superior to the first. I'd just suggest maybe watching some British TV to hear how British people speak and that way you could try to make the language seem more genuine in your writing. For someone with English roots, it's occasionally jarring to read Draco thinking of his friends as "buddies" and so forth. It also doesn't sit with his socio-economic status, because Britain has a very entrenched class system, and someone as well off as Draco probably wouldn't really have been brought up to use language that familiar.
Also, either Crabbe or Goyle was killed in the Fiendfyre during the battle of Hogwarts, so you'd hope Draco would be seeing more of Neville than whichever one of them it was.
Finally, I'd have to say I think your fic had potential, but nothing really happened in it. You know how you write a story with a beginning, a middle and an end? Well, reading that story, I felt like there was no middle. I kept waiting for something climactic to happen, or for Draco to do something interesting, but really, it was just like the beginning blended into the end. It left me thinking there might be another chapter.
by 
