1. M16 is a current mirror with M15, yes, and the amplified signal of M15 appears at the gate of M8, which is connected as a common-drain amplifier as I see...It looks like a noise-canceling LNA.
What is you have to be cautious with is the M16 drain current can vary by the mismatch between M16 and M15. Not by the process! Current mismatch of sub-threshold current mirrors are bigger, because the accurate current mirrors need the smallest transconductance as possible (=smallest reachable W/L).
So you should run Monte Carlo simulations to test the performance of your circuit, I don't know exactly how the difference of the transconductance ratios affect the important parameters of the above LNA (gain, in/output impedance, compression, noise figure, etc.).
To supress the effect of mismatch what you can do is to place M15 and M16 in common centroid arrangement definitely.
2. If the device regions change a lot over process, supply voltage and temperature, but the LNA's important parameters are good I think you shouldn't worry...a lot
Extra thoughts:
a, estimate node parasitics (at least capacitance) and add as ideal devices to the critical nodes, simulate with them. they can ruin everything
b, ESD protection + pad model (and those parasitics)
c, series input AC coupling capacitance to eliminate DC path when matching transformer is connected
d, supply noise filtering
e, constant-gm current reference is recommended
LNA design is a challenge, good luck!