I've cut my first cable housing using this ParkTool page as a guide. The thing is, I think it's a bit too long. Can I safely shorten it or the length is good as it is now?
Update: 7.5cm less, is it better now?
It's too long, and you should cut it again to get it closer to the right length. As a guideline, you could look at pictures of similar bikes online and cut you own cable housing so that the curve ends up about the same.