Requirements, unfortunately, often are not clear from the very start, and more than that change, and actually their change is the part of agile processes, so I cannot dictate business to change this approach.
For tests and investigating bugs - totally agree, I always try to adopt the technique of providing the stakeholders with steps to reproduce a bug, including the very smallest factors - user/login, resetting data to the initial state before reproducing, checking the OS, date, language and so on.
In regards of the bad env, I try to improve it step by step. Even a small step is good, because it's always better to go through 15 steps rather than 16 to start app, to perform some user operation etc.
Thanks for your notes!