This is a very complex question. The Arch people were to NOT able to get a decent Qubes template even though they CAN kick Qubes developer ass blinded and one hand tied behind their backs. Arch has the best software people and documentation. Did I kiss your ass enough?

One of the problems is the update/installation networks. Arch handles most hardware like a champ. At this point torrents are your best bet.

Maintenace screen time is another problem. If it is more than 5 hours a week, you lost me. I hate screen time even TV and sometimes cinema.

The level of skill of the user is also a factor (audience). Arch requires a very knowledgeable user. The Austrian Arch-Crap is just unsecured crap with my rating being toxic.

The rest is standard: reproducible builds, snapshots and the rest of the buzzwords that do mean something.

Let me know if you have a decent Qubes template that I can install the easy way. I did use Arch for a few month and some hardware wizards use it all the time, but they need a truck load of equipment to make it safe and anonymous.

I would 1st (of course) take a look at what's already out there, and done in Arch-land, as a point of reference.

Find out what many users desire, (ex: search social media / forums for popular questions. Not only app-wise, but configuration, features.

I'm just guessing here - really depends what you hope to achieve out of your project.

Most users outside the hardcore Archians, will opt for Arch based, easy guided usage / install.

Maybe you want something more easy to work with - or you could keep closer to traditional Arch, and enhance that?

If security is the idea, usability can take some balance. Kicksecure project for Debian serves as a nice example of usable / hardened, if security is one of your goals (might not be the goal if seeking new to Linux users).

Ask yourself what kind of users are you trying to attract out there. Anything from a distro you always wanted to see on a distro, that you felt partly missing?..

That is where I would start.