2. At present, the tax system forces the promotion of tax control machines that issue invoices. Usually, companies that invoice themselves have to buy and install. If you have a computer and a printer, you only need to buy a invoicing system, which won't cost much.
3. Whether there is no taxable business depends on your taxation method. If approved, there will be no fixed-amount tax business. If it is audited, there will be no business to pay taxes.