I will have a long layover of 21h in between two international Economy TK flights (in one regular booking). I have Miles&Smiles Elite. That gives me lounge access and I wonder:

1. Can I already visit the lounge after landing to take a shower - either with my arriving ticket or my 21h later departing ticket?
2. Are towels provided in the shower? (I heard some lounges charge ridiculous amounts)
3. As far as I understand, there are lockers in the lounge. Is there a maximum usage time, or can I lock my cabin suitcase for ~19h?
4. Can I re-enter the lounge? (so I can go to the city after showering and locking my bag and then come back)

Thanks