Not long or short, but what we call soft (e, i, y, ä, ö) or hard (a, o, u, å). sk sounds like 'sk' before the hard vowels, but before e, i, y, ä, ö you get this softer sound which is similar to sh or ch.
Because "I will quit eating meat" means to never eat meat again (or at least for a long time). "I will finish eating meat" means for example that you finish your steak you are eating for dinner.
I guess it's like this