Yes, you’d have to get a license if you release cover songs to the public but it’s not really necessary for videos that you post on youtube. Occasionally, the copyright owner will request financial compensation or they’ll simply have your video removed from youtube, but that doesn’t happen often…(I’ve heard that certain artists are very strict about having their music copied or covered on youtube…Prince is/ was one of those artists). Most artists allow it because they view it as promo for their music…Your cover can drive new traffic and potentially new sales to the original song. That’s why most famous artists don’t bother having covers of their songs removed from youtube.
For sure! The video doesn’t even have to be professional quality. Think of the video as the vessel that brings the product to the consumer/ listener/ viewer. The most important aspect of the whole package will be your music, whether it’s your covers or your originals.
Here’s a link that explains the steps to follow before making your cover recordings available to the public. https://support.cdbaby.com/hc/en-us/articles/203821539-How-can-I-sell-an-album-that-has-cover-songs-