Isn't 175 damage over 3 seconds too much at level 1?

In a vacuum, yes. When you factor in champion kits, lifesteal, heal on hit items, hp/5, etc it looks less extreme.

For example, Riven's Q will deal about that damage in total, gives 3 dashes, adds a knock up and empowers her basic attacks all at lvl 1. In a vacuum it sounds busted but until you look at the bigger picture.

I'm sure I could figure out what you are talking about specifically, but could you please save me some effort.

That is less than an aatrox q at level 1 right?