So you basically recovered 3 files, one is a full wallet.dat file and the other two are just addresses? The litecoin wallet file could be recovered, however if there are no private keys associated with the other 2 texts you've recovered, then basically you cannot recover them unless you have your private key or your wallet.dat file.
As for your second question, I suggest you try to just join a pool of the coin you are trying to mine. That's easier than to solo mine and most pools only ask for 0.1-1% of your mined coins which I think wouldn't hurt the bank. Best coins today are zcash and ETH for me since even with the difficulty adjustments, it still gives you the best profit for your cards.
Ok, just to clarify. I am able to use the Litecoin wallet.dat file, which I have successfully imported into a fresh download of the qt.
I have 2 other wallet.dat files, however I have no idea which coin they are associated with.
The text file had a Dash coin address which I have been able to look up on the block explorer, and is a real shame I cannot use now as there are several dash coins associated with that address
So all I am really asking now is, is there any way I can identify what coin the other 2 wallet.dat files are for, I have the wallet addresses from the .dat files which I was able to get using a hex editor.
Cheers