Q: Do I need to keep Whirlpool running on my desktop to keep getting new cycles?
A: If you want to cycle your coins then Whirlpool needs to be running. If you have already cycled your coins (meaning they are in the post-mix "account" in Whirlpool) then keeping your client running will make you eligible for free additional cycles, or "remixes". The longer you keep Whirlpool running the more cycles you will get for free. If you are confused about pre-mix and post-mix, learn more about those terms here.
Q: Why is Whirlpool so expensive?
A:Whirlpool is the lowest cost and highest quality CoinJoin service on the market. Instead of making you pay a fee based on the amount you are cycling, Whirlpool costs a flat one-time fee for each new UTXO that you add - regardless of the amount. You can learn more about fees here. The flat fee system means, the larger amount you cycle in Whirlpool the cheaper the overall fees.
Q: Should I move my cycled UTXOs to another wallet or cold storage?
A: Unless you are an expert you should avoid moving cycled UTXOs out of your post-mix wallet except for when you need to spend them, as by spending out of post-mix to a wallet without any post-mix spending tools (such as cold storage for example), you would lose out on the privacy features and spending tools available to you in post-mix in Samourai, as well as losing out on the ability to re-cycle those UTXOs from post-mix additional times for free. Ultimately the choice is still up to you, and you can move cycled UTXOs from post-mix to any destination you require.
Q: Why is my second cycle on a post-mix UTXO taking so long?
A: Additional Whirlpool cycles from post-mix are completely free of charge. That said, you are queued up with other post-mix 'freeriders', waiting for your chance to be included in a free 'remix' cycle. This can take longer than the initial Whirlpool cycle, and is also more reliably carried out via Desktop GUI, as opposed to via mobile.
Q: What are some privacy considerations when spending my cycled UTXOs?
A: For more detailed privacy considerations on spending cycled UTXOs, see this guide.
Q: I'm about to enter Whirlpool, and the fees seem higher than expected. Why?
A: When considering the cost of your Tx0, there are a couple of factors to consider. First, if you have many inputs that you are using for your Tx0, the transaction may be large in 'size', which would result in higher miner fees for that transaction.
Second, if you are entering a very large amount into a smaller pool, you would again create a 'larger' transaction and have higher miner fees, and would also pay higher fees via the per UTXO premix miner fees, required to pay the miner fees for your first cycle on each premix UTXO.
As a general rule of thumb, make sure to enter larger BTC amounts into the larger denomination pools, so as to save on miner fees.