Bathroom adaptations for Parkinsons?

Hi awesome people! Looking for your thoughts. I'm upgrading my da's bathroom because his Parkinsons and other health issues are starting to make all that a bit more difficult. Symptoms that I know of include faigue, balance, dizziness, foot control, some vision issues.

What is most challenging about the bathroom and what would you recommend? I'll consult with my da of course but he'll be reluctant to be specific (I would be too!).

So far I have read about higher toilets, grab rails near everything, a shower seat, non- slip mats.

Your advice is very much appreciated, you are the experts!