Also tbh I think it definitely needs a script. To many pauses or um's can drain the watchers attention and cause them to click off. Also helps mesh what your saying together so it doesn't feel like your just jumping from one point to the next. Also, I heard that most YouTubers and voice actors usually keep a cup of water around to take sips from to keep their lips and throats from going dry. Probably would want to use that, makes your voice clearer even if you can edit it later.