So a lot of this is going to be difficult to answer as it depends on the work culture and individual personalities of coworkers.

• Fidgeting is generally fine as long as it’s not noisy fidgeting. If it’s something like pen clicking, that is more likely to bother someone. Passing depends on the layout. If there is decent space you should be fine, but if it pushes you really close to other people it may make people uncomfortable.
• People will almost certainly see your screen, whether they care what is on it is pretty dependent. If them seeing it makes you uncomfortable, some offices allow the addition of privacy screens which may help and is worth asking about if it will improve your quality of life.
• Some places make a big deal of always looking like you’re on task while others just care about output.
• Downtime is pretty much the same as the previous answer. Depends on your management and work culture. Might be an easier sell if your reading somehow relates to your work.
• People will be able to hear, but talking is generally acceptable at a reasonable volume. Just be considerate of those around you and don’t distract people if they are busy. Along this same lines, you’ll also hear other people’s conversations. That’s why I wear my loop earplugs age have headphones for music. Helps me focus when I need to.
• I did not disclose my ADHD, but also didn’t request any accommodations since I can have my earplugs and headphones which is really the only thing I needed. I’d love to have an office so I could close people out when I was especially busy, but that doesn’t really fall under reasonable accommodations.

There is almost no evidence to back up their claims. It is a whole lot of “might”, “suggests”, and “possible”. It’s great if it works for you, but for you to say it’s superior to prescribed medication is still more harmful than helpful. I support more research into medical use for cannabis, but people who try to claim it treats everything only hurt the movement for wider acceptance.

An actual systematic review showed a lack of research, and currently very little evidence of benefits.

There is no grow at home remedy that works the way my medication does. To make claims like that it’s ignorant and harmful to people who do actually need medication.