So I have this Packard bell dot S since 2010...and sometimes since two weeks I noticed that moving the screen can cause graphical glitches (white becomes bright pink, black grey and blue greenish)...
Is it fixable or am i better of buying something more modern and with better specs? If possible with more RAM than the 2 GBs I have currently...

I also broke the sound jack and a small metal part of the ethernet port...

 

For most netbooks I find "throw it away" to be the useful thing to do. I might repair one or two for myself if I am bored but if you are paying me for replacement parts and maybe two hours of my time it is not worth it as even after that you are still left with a piece of junk (they stopped making networks when tablets came on the scene and most were never any good to begin with).
That said in your case it is probably the classic laptop maker made a cable about 2mm too short and after a bunch of open/close it got pulled and fractured. If by some miracle you can find a replacement cable then you could bring it back I guess. Note that most replacement screens will not come with a cable, and while replacing it is not a hard thing it is also not something I would attempt as your first go at electronics repair. Also if you are tempted to buy one from ebay for spares and repairs then it might be the same issue (it was really common on laptops from around then, and to this day and likely in the future as well) so it could be good money for a similarly damaged or likely to fail product. If the sound and ethernet are also damaged and you want them then it only gets more expensive.
Though looking at http://www.maboutiquemicro.com/services.html if they reckon 45 Euros for screen replacement then I doubt you can get a nice refurb laptop for less ( http://www.pixmania.fr/informatique...rdinateur-portable-reconditionne-20200-s.html seems about right for refurb/reconditioned laptops).