I don't know the Core wallet that well.
Maybe it shows you the value at the time of the transaction.
In any case the value shown in the Core wallet is not that important.
The value you would receive depends on the market where you are going to sell the bitcoins.
You have used many inputs which made your transaction bigger. The fee you have chosen is 35sat/B which is too low because the mempool is full. (this is a big problem with Bitcoin SegWit and why Bitcoin Cash has forked in August)
Fortunately you have enough fees to accelerate it here: https://pool ...
My guess is that you are using hashflare.io for the cloud mining.
I don't know why the tx can't be seen in any other block explorer. It could be that they don't broadcast the tx and will mine it themselves at some point. The transaction fee would be too low to get included by other miners at the ...
I don't think you can import the armory wallet to any other client.
You could export the private key from armory and sweep the bitcoins into your new wallet. (Meaning a transaction will be created to move the bitcoins to the old address from armory to the new address in the bitcoin wallet)
You should never give your private key to any other person or homepage.
If someone is asking you to do this it is very likely that they want to steal your bitcoins.
What is it you want to do exactly and what 3rd party wants your private key?
If you use the bitcoin.com wallet you will have to wallets but both use the same seed and thus should receive the Bitcoins. A problem could be if you transacted more with Bitcoin Cash and thus the addresses have advanced more on that wallet than on the other.
Electrum works only for Bitcoin.
The Electrum client has been forked as Electron Cash to support Bitcoin Cash and can be downloaded from https://www.electroncash.org/.
You should be able to use the same seed as with Electrum to create the Electron Cash wallet.
The Bitcoin SegWit chain is congested and the mempool is very high thus transactions can take very long.
(Although it is interesting that the transaction is not even in the mempool)
Did you check with Bitpay given that both the wallet and the credit card are from them?