A:AnswerLori, the Roku Voice Remote Best Buy sells will work with your Sharp TV
https://www.bestbuy.com/site/roku-voice-remote-black/6367484.p?skuId=6367484
A:AnswerToo bad Sharp answers are always "contact us".
Yes, there is an app store, both free and pay available.
And I just did a search and your channel is available.
A:AnswerYes and no. It comes with Roku, which has the YouTube platform already installed on it. You still have to register and login with your own subscription/account, though.
A:AnswerYes! YouTube and many other streaming platforms as well. Roku is awesome. Just be aware that the unit is WiFi only, meaning no direct connect to your internet via Ethernet. Must connect via WiFi.