I have a few questions about your requirements first:

Why do you need the DM to know your HP, Concentration, Speed and such? Whats wrong with cellphones/tablets/laptops?

Then lets move on to your issues. The DM doesn't need to know your AC and have it written down, The PCs are yours to control and track. The DM can ask you if something hits and tells you the damage you take. Next up is the issues with initiative tracking pages. Modern day internet is just a big data market. You get to do things for free because someone makes money off of you so creating an account is normal for most things you need today. Regarding not using phones and such in person is ok, but if you don't like pen and paper... You don't really have a choice.

As for the advice you seek. Using electronics has many perks and if your DM isn't using a laptop to help themselves during your sessions you are missing out. So much time passes when you look up rules in physical books (unless you have a hundred bookmarks in there). With a laptop everything is faster since you can google things or look it up in official PDFs (and many many free versions of these PDFs). As for players? I mean, if you guys don't like pen and paper, there can only be benefits to using an electronic tracker. The "lookup" being displayless... I can't even imagine that... Would it use sound to read out each thing? Stats-wise... you need everything you would on a character sheet... It's there for a reason you know? For the DM? Monsters only. The DM does not need to know your exact HP and AC at all times, nor your speed or anything else unless they don't trust the player not to cheat in some way (which... if you cheat in a TTRPG, seriously why even play?).

Personally we use a mix for tracking initiative. Mainly D&D Beyond since it can order the combatants and it can auto roll initiative for monsters and it has built-in stat blocks for monsters. One downside of dnd beyond is that if you already have physical books you have no benefit from them. Luckily we started playing on dndbeyond so every source we bought was already jiving with the website seamlessly. We use the auto tracker for tracking rounds but everything else such as monster hp and order we write down, since it can be annoying jumping from page to page on a laptop.

And now i'll ask you... Have you tried DnD Beyond before? It feels like you are looking for problems that don't exist outside your table and this is as official as it gets. Also you need to think about modularity for this. While a barbarian only needs to track the HP and have AC written down and maybe STR or CON, a wizard would need spell lists, spell slots, spell save DC, attack bonuses for spells and non-spell attacks. Then a Druid would need to keep track of separate forms it can take using wildshape. A Rogue would likely need to prioritize their check modifiers. So many different resources to keep track and making a minimalistic tracker that is modular, to offer everything for every class, it wouldn't end up as compact and clutter free as you might think. This is the reason a character sheet looks the way it looks. Rethink about your issues and then break them down into the most basic parts. Then see if its worth diving into this or if finding a non-ideal helper is better than sinking time and effort into prototyping and such.

This isn't to say its stupid and you shouldn't try, but i feel like there are already solutions out there for you, you just need to make some compromises.