When we do not really need the money and that we can cover our expenses with our fiat money, it would be wise not to use bitcoin with this scenario and you can getaway with he transaction fees. However, if you want to trade, then you have to decide and target gain that covers also the expenses.
That is right. Constantly moving your bitcoin from one wallet to another or withdrawing them for unnecessary transactions will only incur transaction fees. Avoid them if necessary. If you need to withdraw then it is good to withdraw more than enough to avoid another withdrawal in a little later.