Thanks for all your work and the quick fixes! As aceshigh said this is a fully, and surprisingly comfortably, playable port
I'm loving it!
I guess what this port could use the most now would be even more touch-focused controls. Like I said, I don't like the "swipe to turn" function, whereas I think switching levels by swiping with two fingers works well and makes gameplay a bit more fluid, especially when embarking from the Skyranger. I just sometimes find that you switch levels too quickly, making you sometimes "overshoot" and switch several levels at ones. Maybe the range for swiping until the view changes 1 level should be higher, or maybe it would even be a bit more comfortable if you could only switch 1 level at a time, but I'm not sure.
Concerning opening doors, a natural way could be that they are opened by long pressing on them, but only when the selected unit already stands next to it and faces it. This way, if a soldier walks up to the door, the first long press on it might still make him only look at the door, if that's what you want him to do. If you want to open it, another long press would do that.
Regarding "force firing": When I started playing OpenXcom, I hoped it would be automatically triggered if you tried to shoot an enemy again when no line of sight is available. I don't know how hard that is to program, but it would again be a rather natural way of doing it without the need for an extra button. You would just aim and tap on the unit, which triggers the "No line of sight" warning sign, and if you still do it again, the unit would just "force fire".
Finally, I've read that in OpenXcom on PC you can cancel a unit's movement by right clicking. I understand that this means you can stop a unit while it is already walking? If so, that would be another great addition to your port. Since you can't really do anything else while a unit walks, anyway, why not make it so just tapping (or double-tapping so it doesn't happen accidently) anywhere during movement would stop it? This would also reduce the severity of mis-tapping.