I'm lucky enough to have a low-vision person who works as a tester on my team, and does our accessibility testing. It's very impressive watching/listening to him use a screen reader - I was really amazed at how fast he has it set to read the screen.

He does suggest all the things you've mentioned above, and it's good advice.

However one thing he also says is: don't assume that low-vision is the only type of disability. You also need to build software for people who are: deaf, have slow motor skills (e.g. avoid putting strict time limits on user actions, or making things jump around on the screen too much while people are trying to hit a target), lack fine motor skills (e.g. don't make a target too small), etc.