Garageband on iPhone: In need of some conceptual hints

Hello everyone!
Since I'm new here, I thought I'd begin with a very brief paragraph of introduction: My real name is Felix, I'm from Germany, I work as software developer in assistive technology, and I'm blind. I'm a huge fan of a lot that Apple has done, and is doing, accessibility-wise. It's great to be here, and I hope I'll be able to both contribute and learn a lot while being here.
I'm currently teaching myself to use Garageband on an iPhone, using an iRig Keys Pro midi controller to play software instruments, with some success. I intend to share my findings here in the form of a guide at some point, when I get around to writing it. And if my music serves as conceptual demo I'll share that as well.
For the time being, however, it seems that I am the one in need of some guidance. Especially, I can't seem to figure out how to do basic things like trim a region, trim a sample (as in: using the sampler) or extend the length of a looping track. I find it's hit and miss, sometimes reading the time as I drag, sometimes not reading it, sometimes not even moving the slider that I'm trying to move. Also, actions on the rotor of a region, like trim or loop, are there but when I select them and double-tap more often than not there is no feedback, and I can detect no difference afterwards.
The most frustrating thing, however, is that Garageband has a terrible tendency to crash when I switch from tracks view to perform view, when I undo an editing operation, or even when I try to exit out of the song so that it saves. I've lost quite a bit of editing this way. Irretrievably, I might add.
So my questions, to which I hope someone on here might have an answer, are:
1. Does anyone have an idea how to prevent those very frequent crashes?
2. Is there any documentation, or similar content, regarding editing tracks and regions with Voiceover?
Thanks in advance!
Greetings,
Felix