See below. 3/week dialysis can only acheive about 20% of what "cleaning" your own kidneys can do. So more dialysis cannot "kill" you but is not practical at the present time. Blood pressure changes ie typically low BP can cause problems.Night time dialysis and home daily dialysis are options to explore. Kidney transplant if possible.
Not if controlled. Some people have great function from their own kidneys but will never have adverse effects because of it. With the replacement therapy, the amount delivered is called the "dialysis prescription" - and is a balance of what the gov't or insurance companies will agree to pay for, and what works well over time for a large number of people. For the individual pt, more (well done) dialysis may be ok.