Does anyone know/remember this Youtuber?

Etenks?

Bingo! It was etenks1. Unfortunately, all the videos from the first channel were long deleted. His second and third channels don't have these videos either, but they were a nice way to show new trains at the time.

The first thing I recall seeing from him were two or three low quality videos where he went over various characters and gave each one harmonica "whistles" and "horns". He won some stuff in one of Leokimvideo's giveaways as well. When the 2012 RC Thomas was new, he ran him with Annie and Clarabel on a poolside TOMY layout (not like Pool Tracks).