I think that looks like a great commuter; especially if you have a commute that is largely gravel/trail. If it's all paved, then you would want to replace those knobby tires.

As for swapping with tiagra 10sp, I could be wrong, but I thought that normal freehubs can accept 8-10sp cassettes, but for 11s, hubs were redesigned to make room for the extra gear. So if you wanted to make a component swap, you'd have to swap rear wheels too.