How can I make my startup's website ethical?

You have covered most of it, perhaps just expand the scope of the 3rd party tracking to make sure your users aren't being tracked by CDNs, cloud hosting etc owned by the ad networks.

You mention dark patterns, I think its good (and honestly healthy for business) to implement better-than-average product transparency. So have pricing very obvious and easy to find, little Q&A on refunds with refund process quick and fair.

Finally -the obligatory - talk to your customers :P What do they think an ethical site is? What do the crooks in your industry do that annoys them?

Think about accessibility maybe?

Also, make stuff that don't need Javascript to work when Javascript is off. Privacy-minded people might disable Javascript.

Avoid lying and unsubstantiated hype: don't say you can do something you can't. Some people are tempted to do that with investors, hiring, PR. It's a short-term optimization and no good will come out of it in the long run, even from a purely amoral standpoint.

In my experience, the conversations we had with our clients, advisors, investors are really good because even when they make a mistake assuming something, we correct it on the spot: "No. We are not able to do that right now because we have B issue and we're working to solve it given we do not have expertise on this. It will take some time. For now, we're doing Y instead because of X. We don't have Z capability".

The trust that grows from having these conversations is invaluable. You can't build it back when it's gone. Even if you're not in a managerial or executive position and your manager makes the mistake of wrongly claiming something, you pull them aside and correct them. They most likely thought what they said was correct, and will follow up on that and send an erratum/clarification.

I mean firstly know what "ethical" is, ethics is extremely complicated, and what is ethical is obviously debatable. Is it purely utilitarian? Or is it something more complicated? People will clearly and not reasonably argue that any non-violent commercial endeavors is ethical, others that anything that consumes resources unnecessarily isn't ethical.

If ethics were something we could relate to use in an actionable way it would be so simple it wouldn't be necessary to do so.

I think the best way to make the website more ethical is to respect user's time, clearly provide the content they are looking for and don't put psychological triggers (such as LIMITED DEAL 90% DISCOUNT, 30 SECONDS LEFT) or annoying newsletter pop-ups.

If you want to go self-hosted with the analytics, but still need enough user data to test hypothesis or improve conversion rates you can check out the self-hosted platform I'm working on: https://www.usertrack.net/

Ideally, websites should load zero third-party resources. Every third-party resource is another third-party that can track users.

This includes avoiding CDNs.

Have a fair refund policy. Refund unused months if a paid user purchased the yearly subscription.

Do not ask for the credit card during the free trial signup.

Plant a tree for every visitor. I dunno.

Make it screen-reader friendly. The modern web sucks for the visually impaired!

Avoiding Facebook Pixel / GA / probably other retargeting vendors is cutting off one of the (by far) most effective marketing channels available to companies. It's your decision, but if you don't like advertising, you're relatively unlikely to succeed at sales.

LibreJS compatibility comes to mind.

Turn it off?