Hi,
I do not really understand what your graph do (a lot of wires !), but one advantage of Dynamo over Grasshopper is that you can work with lists and manipulate them quite easily. Instead of creating as many nodes as objects to your lists, try to feed your entire list to the node you want, and evenetually work on lacing. The List.GetItemAtIndex nodes do not seem necessary if your are doing it for each element you have…
If you desperately need a loop function, there is a node : LoopWhile. There is also another wxay to do it : Force dynamo to rerun the node multiple times
Eventually, you can work on your list structure. You can for instance create a list that contains two lists : the list of your rooms and a list of parameters that go with each parameter, etc.
Hope this helps