how to deal with whois lookup privacy?

Any decent domain registrar provides WHOIS privacy for free (just note that that might not be available for .eu domain names). Additionally you can always use fake data on your account, but in this case you might lose your domain if they decide to check it.

other issues I may run into if I chose my own domain

When registering a domain, always look at the renewal price: often the first year costs relatively low, but after that there’s a steep price increase.

As for an email hosting service, in addition to the ones you specified in your post, I suggest you to look at migadu.com.

I use DuckDuckGo’s email proxy service, you can sign up for one custom email and generate any amount of temporary-use addresses for the ones you don’t trust to stop spamming when you ask them to. The purpose of their system is to be the address you sign up with, and they do their best to strip trackers and garbage, and forward it onto an email of your choice. You can change the forwarding email at any point, so it can be incredibly useful for a transitioning period.

I use Mailcow dockerized for a home domain, it is actually a very acceptable price for me being able to:

• Control my own DNS rules (it was a nightmare trying to use DuckDNS for an mailserver because of the rules you need to set)
• Run through a reliable service because DuckDNS occasionally went down, making my domain unreachable and breaking external access of any server I run
• Have a personalised public home for myself, if I ever want to make blogs or provide public services or something

I used a very lovely and helpful YouTuber’s guide for it, Opentaq (here)

i’m using mailbox.org with my own domain.
works like a charm.

I’d say it’s worth it. Another bonus with your own domain is that you basically have an infinite amount of receiving email addresses you can use for no extra charge e.g. you can just keep making up new email addresses @ yourdomain whenever you need to register to a new website or whatever.

Drastically cuts down on the amount of spam you get at your main/personal address(es). Also helps whenever a website or whatever has a data breach, just means your random made up email address was leaked and it’s easy enough to mark that as spam going forward.