ShuttleCF

Ski total a handful times ever, never learned pizza turns, using not so good parallel turns (learned from watching video), with rental ski(beginner-short one) can go blue/green in Pennsylvania resorts without trouble, but I so far I only ski slowly and always make turns when skiing, do not want to lost control, never go straight down hill. I have good agility and quick reflex( in other sports, not yet dare to use it in ski), willing to train my legs to be more powerful.

Start to like ski a lot, Just bought a pair of used:
Nordica Dobermann Spitfire Pro EDT 122 72 105 R 12 M (2009 version?)
which reaches to my chin, was warned by seller that this ski is for racers, and since I just ski a few times, I need to be very careful with it.

Here are links for the ski:
ProductWiki: Nordica Dobermann Spitfire Pro EDT - Alpine Skis
Nordica Doberman Spitfire EDT XBI CT 2010 - 2011
Nordica Dobermann Spitfire Pro EDT XBI 2011 | Skipinions.com, Ski, Snowboard, ski resort and accomodation Reviews
Nordica Dobermann Spitfire PRO EDT

I am worried about if I can handle it and use it up to black diamond. I just wish I can grow into the level that I can use it and also, it is enough to handle all the black diamond for resorts only.

Can someone with more knowledge and skills give me some advice on what should I be watching out using this ski? Or should I just buy a intermediate one and start from there?

Thanks!