When I first decided that I wanted to keep bees I knew I wanted to do it all natural. ... Just a little reassurance I can do this ... I don't mind work or research
I hate to be the one to burst an idealistic bubble - but the keeping of bees is NOT natural, it never has been - so no, in an absolute sense you can never keep bees naturally.
What you CAN DO is to go some way towards accomodating the bees' natural behaviour - such as running a hive foundationless for example, rather than using man-made foundation. What this means is that the bees then decide for themselves what size of cells they will create when building their combs - after all, it is those combs which actually constitute the bees' home, rather than the hive itself. That's just a box which houses the combs, and within reason, the bees will adjust to living within any old box.
With regard to treatments, there's a growing number of beekeepers who have adopted a totally treatment-free philosophy. Then, at the other end of the spectrum, there are beekeepers who rely upon a chemical solution for just about very possible ailment - real or imagined. And then there is a third group (which is where I'm located) who don't treat bees for diseases, but do 'treat' (as in 'kill') their parasites such as Varroa mites and Small Hive Beetles.
I'm not a great one for handing-out advice, but you could do a lot worse than reign-in your idealism for a short time, and just get on with the keeping of bees in whatever style is available to you - while you learn the basics. Then, once you have a season or two under your belt, you'll be in a much better position to make an informed judgement about which style of beekeeping is 'for you'.
It's a great hobby, totally addictive, and although the bees will never become cuddly pets, it's almost certain that you'll become extremely fond and protective of these amazing little creatures. Most of us do.