There’s a search button at the top 
Anyway I will not add adjustments to the lyrics, you need to fix the tags on the provider. Adjustments without value saving per song is useless. And well value per song is the role of the tags or the provider.
Symfonium should perfectly understand the [offset:] of LRC files (LRC (file format) - Wikipedia)
For the thumb again I already said no a couple of times as it’s absurd to duplicate the now playing screen in the lyrics screen, lyrics should be visible directly in the now playing screen as more logical. But in that case the only proper place would be at the place of the thumbnail.
With that said I currently have no idea about how to handle all the case of showing the lyrics in every now playing variations so I’ll think about it again, but this will also require a specific landscape lyrics view too…
And please no need to write a novel to explain me that I’m wrong 