Hello there. First of all, thank you for getting in touch with us. This is all great feedback and we really appreciate your time in writing this. We feel honored to receive your offer but at the same time we wouldn't want to make anyone work for free so if we ever consider hiring a QA tester we will think about you. For now we already have more tickets that we can handle and it might be an overkill.
We think we understand what parts of the game need to be improved but at this point we are having a lot of issues with Game Maker Studio and our source code itself. We are considering making the project open source and maybe try to move as much as possible out of the Game Maker Studio ecosystem so it can be easier to manage.
We will create tickets for the issues you reported and hope to get back on track fixing and releasing updates!
Thanks again!