Timings - am I overthinking this?

Yeah, I get that processes are done on clock edges,

So, when my 50MHz clock has its first rising edge, I am setting the address onto the memory address inputs, and taking the memory clock high (causing a rising edge there). Then, when the 50MHz clock has its second rising edge, I am reading the data from the memory data outputs, and taking the memory clock low (causing a falling edge, which does nothing, except make it ready for the next rising edge).

That's what I meant - sorry it wasn't clear :-)