Yes, Bisq wallet is a real wallet with Bitcoin addresses that only you control.
When you move your funds from one to another address inside or outside of your wallet, you need to pay a mining fee to the Bitcoin network so they include your transactions in one of the next blocks.
When the trade started you deposited your BTC into a multisig address that you, the other trader and the arbitrator hold the keys for. When the trade ended your security deposit and your BTC trade amount moved to the address that only you control.
You can go to Settings and change the withdrawal fee to whatever you like. I assume 10 sat/b should be fine.
The “mining” process concerns a whole block of many transactions. (It happens every ~10 minutes).
When the block in which your transaction is, is mined/sealed, you have payed the fee, and its finished. You pay the fee just once.
I think @Dynamata meant to ask if the mining fee will not be necessary when all Bitcoins are mined (in about 100 years).
No, that is when it will be even more crucial that Bitcoin transactions have a mining fee, since miners will not have newly minted coins as a reward, just the mining fees from the transactions that they included in their block.
No. The process of mining is actually just gathering transactions that were broadcasted to the network and structuring them into something called a block. All of the Bitcoin blocks have to be in a certain mathematical relationship with each other where together they make a chain (blockchain).
Figuring out how to make a block that is in this relationship with the other Bitcoin blocks is a very computer intensive work (basically just guessing the solutions, brute forcing).
For this work miners get paid in two ways, they get newly printed coins and they get whatever mining fee the transactions that they chose to include in their block. This mining fee can be set by the users to whichever value they want, but blocks are limited in size by design, so users compete with their mining fees to get included in a next block.
Mining fees are there to motivate miners to get transactions included in the blocks and printing of new bitcoins is a way of fair distribution of coins over time and a way to motivate miners to mine blocks when there aren’t many transactions (early days of Bitcoin).
There are many youtube videos that explain the process of mining in Bitcoin
“Eventually, predicted to be sometime around the year 2140, all Bitcoin will be mined and there will be no more Bitcoin rewards. Mining will cease. Miners will instead turn into transaction processors and be rewarded with transaction fees”. (Crypto Revolution by Sam Volkering)
Anyway, now BISQ will not connect to network so have to recover my account.
I guess the author of this quote wanted to make a distinction between the process of mining before and after all bitcoins are mined so he stopped calling them miners. In reality the process will not change at all, miners will be running the same algorithm and do the same work.
Do you have any open trades or offers? If not, you could try going to Settings->Network Info, then click on the “Open Tor settings” button and then the button at the top to delete the outdated Tor files. That might help.
Look at the dates when those backup wallets were created in that folder.
I think all you need to do is replace bisq_BTC.wallet in the wallet folder with one of those backups and restart the app.
So try finding the a wallet file in that folder that was created when your Bisq app was working correctly (before the duplicate transaction error), copy it and paste into the wallet directory, move bisq_BTC.wallet somewhere else for safekeeping and rename the backup file that you pasted into the folder to bisq_BTC.wallet.