Layout floor plan and block specific layout guidelines
Quantitative information sheets for each block and each transistor in those blocks
Point of failure with respect to Supply and current
For each circuit block the headroom constrained branch and its worst case headroom requirement. Of course that has to be below the minimum operating supply voltage and even the lowest operating voltage which may be the UVLO falling threshold.
Any spare or unconnected devices should have a good reason and a plan behind them to be there. For example spare mirrors should have a reason what current would you need to adjust. Spare transistors for putting circuit in shutdown should have a reason why they are already not connected.
Bipolars anywhere? Consider carefully whether they can go into saturation especially during startup/shutdown and what happens then.
What is the matching of each matched pair and mirror should be analyzed and numbers kept handy.