Can old wallet.dat (offline long time) still receive money?
Can old wallet.dat (offline long time) still receive money?


Yes. If you have the addresses from that wallet, coins can be sent to those addresses.


  I think that I remember that 100 private keys are generated in advance and are in stock of the file. Does that mean, that I can receive 100 transactions after taking my client (it was bitcoin-qt/bitcoin-core) offline?


An address can receive coins more than once, although it's considered best practice to try to avoid that. But, in practice, you can receive many transaction that pay to any of those 100 addresses.