Hi gulkaran,
you are welcome.
To your first query , you can reduce no.of spliters to a number till it serves your requirement and purpose. You should try to get better results first and then go for optimization.
Secondly, just place the amplifier after fiber in downstream and before fiber in upstream. here i would like to mention it is not recommended anywhere but i have observed better results doing so.
p.s : use optical amplifiers in both directions.
Lastly, i would like to say that i am not aware about your design implementation , so i am not able to figure out what you mean.
Regards