I would like to place the blockchain files in a different location than wallet.dat. Is this possible with Bitcoin Core? 
(I would like to avoid symlinks and "-datadir" is not a solution...)
(I would like to avoid symlinks and "-datadir" is not a solution...)
Code:
-wallet=
indeed.Well if zou are looking for all of the options you can visit: https://en.bitcoin.it/wiki/Running_Bitcoin
and as for example
Quote
Wallet options:
-disablewallet Do not load the wallet and disable wallet RPC calls
-paytxfee= Fee per kB to add to transactions you send
-rescan Rescan the block chain for missing wallet transactions
-zapwallettxes Clear list of wallet transactions (diagnostic tool; implies -rescan)
-salvagewallet Attempt to recover private keys from a corrupt wallet.dat
-upgradewallet Upgrade wallet to latest format
-wallet= Specify wallet file (within data directory)
-walletnotify= Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)
-spendzeroconfchange Spend unconfirmed change when sending transactions (default: 1)
-disablewallet Do not load the wallet and disable wallet RPC calls
-paytxfee= Fee per kB to add to transactions you send
-rescan Rescan the block chain for missing wallet transactions
-zapwallettxes Clear list of wallet transactions (diagnostic tool; implies -rescan)
-salvagewallet Attempt to recover private keys from a corrupt wallet.dat
-upgradewallet Upgrade wallet to latest format
-wallet= Specify wallet file (within data directory)
-walletnotify= Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)
-spendzeroconfchange Spend unconfirmed change when sending transactions (default: 1)
There is a list with all of the command-line options that you can use while running Bitcoin Core.
If something is not on that list - it do not exist
Regards.