You should have asked for the hotel in MAN, not the hotel in KRK. The first is covered under duty of care, the second is not.

​​​​Transport costs to MAN are probably not covered as it was a voluntary choice (perhaps not "common sense", but at least follows some sort of logic).

In my recent rebookings onto LH I have been given the free luggage allowance, so I would certainly ask again for that to be refunded.

Incidental costs like your transport in KRK will never be covered, that's for travel insurance.