NOTE: make copies of these files before you attempt any sort of import or "wallet dump". Only work on copies of the files!The sad fact is that there is no "One Size Fits All" solution for extracting keys from all these various files/wallets... You'll need to deal with each one individually based on the file type that you have and the cryptocurrency involved.
- "exodus.wallet" is most likely some export/backup of Exodus, you'd need to inspect the contents of the folder to see what is in there. Possibly import into Exodus wallet directly (
https://www.exodus.io/download/) or you will find a list of private keys etc.
- "VeriCoin" / "Verium" wallet here:
https://vericoin.info/
- "wallets" and "wallets1":
You'd need to look at what is in the folders, could be almost anything
- "bitcoin-wallet-keys-xxxxxx", "darkcoin-wallet-keys-xxxxxx" and "litecoin-wallet-keys-xxxxx" are possibly just text files. Try and open these in a text editor and view the contents. You will then need the appropriate wallets to import the keys. Note that DarkCoin is now "Dash".
- "default_wallet" is likely an Electrum wallet file. Try opening it with the latest version of Electrum:
https://electrum.org/#download
- "ethereum-wallet.json" is possibly a MyEtherWallet keystore json file... you can open in a text editor to check, but the keys will likely be encrypted. You should be able to import the .json using MEW or MyCrypto etc.
- all the "*.dat" files look like someone has just renamed "wallet.dat" files... there are ways to see what the coins are by simply opening in a text editor and searching for "name", this should hopefully show you the "Addresses" that are in the wallet.dat. The format of the address should give a hint as to what they might be. ie "1Lfsdf43t...." Bitcoin, "Dfg8gjksdg...." DOGE, "L32hsjkd..." Litecoin etc etc
Here is an example of a Litecoin wallet, searching for the word: name
You can see the addresses starting with "L......."
- "XDN" seems to be a worthless cryptocurrency called "DigitalNote":
https://coinmarketcap.com/currencies/digitalnote/ 
- ".rar" files, just try and open with 7zip or WinRAR and see if they contain anything useful. If the ".rar" files have passwords, you'd need to bruteforce the password using the myriad of rar password crackers available (check Google "Rar password cracker")
