1) It is still a little buggy, but they are working on it. I find when I have issues, it is best to restart the wallet. - Also you can check your wallet balance in the online blockchain explorer: explorer website:
http://kmd.explorer.supernet.org/address/YOUR-ADRESS-GOES-HERE
2) You collect 5% interest on KMD simply by holding it in your wallet. Every once in awhile send your self .001 KMD to see that interest in your balance. More info here: https://supernet.org/en/resources/articles/receive-free-coins-quaranteed-kmd-interest
3) This just means you should keep your keys backed up in a safe place like in a local password manager.
4) Not sure
Thanks for the replies. When you say send myself KMD you mean send it from an exchange or mining pool or something to my Agama wallet?
"If you want to accumulate even more KMD you need to get your interest to earn more interest. You won't receive the new coins until you have sent the coins, so the more often they are sent, the more KMD you receive."
Still a little confused.
Interest is claimed when you spend a valid utxo . So send a tx from your wallet to yourself