I would appreciate if open quests would continue and maps in the gaps would soon fill, or continue from the first stages of the game. (Not a new Remgard-safari)
First off welcome to the forum.
The game is still in development so while we all feel your pain and want to complete the open quests as well, we have no idea how much Remgaurd may or may not have to do with some of the open quests. So the only thing I can offer on that would be to patiently wait for the next update.
It would be great if I could decide the game language myself. Currently it is German as my phone is set German. But there have been huge translation difficulties in the past and there are still some little points. I would prefer to play it just in English as it has been in the beginning.
I have seen this before and I have to agree with you language selection would be nice.
When I started the game at the very beginning there had been difficulties when entering the name, so that it is now strange, with 3 lines. An option to change the name would be a nice luxury.
Like you said this would be a nice luxury. I would agree so that I could split a save game at certain points in the game when a choice is presented. I don't think this will be high priority on the development list and nor should it be but it would be nice.
It would be nice to have some sound on/off option within the game. I usually forget to turn off the sound of phone before starting the game

The game doesn't have any sound so that should not be a problem....
I think for the pioneers from the beginning there has been some unfair handling in the development of the skills. Would be nice to get the skill points afterwards at next update.
After the update that included skills my save game recieved full skill points. So I am not sure why you wouldn't have received them.
There has been a version where enemies didn't resurrect next to the character. I enjoyed that. I think it disturbing when having killed a monster, want to drink some potion before continuing, but the monster comes back and attacks . .
.
While this is a possibility it should not be a common occurance. My suggestion would be to enter your menu quickly after battle (as I do) or move to a spot with no Monsters.
I've collected so many little stones. Will there ever be a sling to make use of them?

(missile battle)
It has been talked about on the forums but as of right now nothing has been decided.
A brutal kind of enemies would be such, which appeare in groups and "consciously" encircle the player, trying to get battles with as many of them as possible at once. (8 in the worst case) Such behaviour would fit to mummies or soldiers.
I have heard rumors, of possibilities, that just maybe this could happen....

Give a man a fish and he will eat for a day. Teach a man to fish and he will eat for a lifetime.
Give a man a fire and he will be warm for a day. Set a man on fire and he will be warm for the rest of his life.