A cadet in Thomas Cook is someone with no commercial experience and straight from a flight school like CTC (there have been 1 or 2 exceptions to this rule). All pilots with at least 300 hours time on type (regardless of total experience) have joined on a full time contract. Those with < 1,500 hours total time on the Junior FO contract (lesser pay).
VxVy, I'll answer your question on here...
I'm at a regional base (2 aircraft, peak 3, lowest 1) and yes outside of peak season (May-Aug), I've always had the opportunity to book at least one weekend GDO (some times even both days for weeks at a time!).
Regarding swapping flights: We don't have a Master Roster just yet (there are ongoing plans for this) so this makes things difficult. However, if you ask around via email/forums you might find someone. Then contact crewing to arrange (I believe there's a form to fill in too).
Despite the hardships the industry has faced and continues to, we're not doing too bad. Something like 150 pilots will have been recruited in 2 years with virtually nil attrition.