Sorry for the late reply!
Your best bet for reading? Get the kindle app. Set up a kindle email. Mail the books to that email and it’ll show up in the kindle app. I do use a kindle and I suppose I could copy them over but it’s so much easier this way. Do you have calibre? Another good option paired with stanza front end. You can browse your entire library and move what you need. Can’t answer the other questions but for reading this is your best bet. Kindle email supports mobi, pdf and word. I think txt as well not sure. The only thing that doesn’t work is ePub but with caliber (or any free online converter) it’s incredibly easy to change formats.
I think I did download Kindle (something I'd only do in desperation mode) but there were still some things that didn't work. But the e-mail thing doesn't ring any bells, so I'll make sure to try that.
I did try Calibre as well (I knew it from macOS), also little success.
I was in general shocked by the sheer jailed feeling. No real FS, everything capped... I generally dislike Apple for different reasons but this was just a big 'wtf is wrong with these people.'
Of course, Windows, macOS, and Linux will need a bit of work to get it to my "satisfaction level" where everything runs to my preference, and I can wrestle with the occasional error that may come up and so on. But this iOS thing? I knew it was crap by fiddling with my friend's iPhone's (with the whole "this doesn't play Flash?" era) and whatnot (don't understand why people still buy those overpriced digital prisons but that's for another discussion) but feeling it in my hands... Oh god. It feels wrong. I admit my background may have a lot to do but still... My girlfriend is a regular user, and she's always asking how can she do this or that and sadly the answer most of the times is "...you just can't. You need a real computer/laptop".
And goddam the iPad Pro is not cheap (it's Apple unmistakably), and it's incredibly capped. Why on earth would they do that? I understand newbies need not worry about fs's and whatnot but there should be a way to get your hand in the machine and make it retarded-free.
I'm sorry for the rant.
The most amazing thing I find, is people who don't research something before they buy it then complain about it.
If you are referring to me, I clearly stated that my only reason to buy the iPad was for drawing purposes and that I had no complaint in that regard. The iPad Pro seemed to be the best option for drawing purposes. Otherwise, I'd have bought a tablet with a real usable OS like Android.
For most the iPad when used as intended there is not a need for access to a file system, thats the ease of it.
I just posted a very sensible "used as intended" case, and
it doesn't bloody work. This is not a matter of slogans or "you are holding the device wrong," right? If I can't accomplish the most straightforward task such as reading a bought ebook in a purchased product, famous for it's reading comfort, in case you don't know, the blame is on the product. That's how the real world works outside of the Apple bubble.
I guess what this thread shows is there are tons of ways to do things on the iPad, mainly because there are over a million apps in the App Store.
That's reasoning is a bit flawed as I downloaded no less than twelve "file managing" apps. Guess what, all apps are bound to the same restrictions. Therefore it makes no difference if there are one million or two trillion apps, it's the terrible iOS who sets the rules. And the rules suck.
Due to the limitation of the file system it is necessary to develop your own set of workarounds to achieve simple things. And depending on exact what you want to accomplish, different workarounds and/or costly external devices and services are needed.
Nothing straightforward, fluid or consistent about it.
Amen.