You are right.
However, with wpdm pro you can check stat from Downloads > Stats that will show who from where downloads it. Form lock is mainly used to integrate third party contact form. with wpdm pro you will get email lock feature to collect email who downloads.You can decide if these are necessary for you. It is up to you. I don’t know your requirements.
You have understood correctly for download notification addon.
All of our products update annually.
Those will be auto renewed after one year.
However, you can cancel the auto renewal anytime but in this case, though you will be able to use the plugins, you will miss the updates and pro support.