Yes bitcoin is taxable. Not by means of the government is taxing but I guess that the miners were the one who are asking for taxes. The confirmation is dependable on how much btc you spend. If you will spend the high amount in sending then the confirmation of your transaction will be fast.
Of course bitcoin is taxable. When we talk about bitcoin, we will talk it as money. Everything that connected with it, it will be taxable. Your opinion about the miners were the one who are asking for taxes is acceptable. Maybe the tax will came up when you sell or buy it. It will not occur when we still hold it.