To conclude these series of postings, here is an observation to ponder.
Does this mean with fewer than 5 people you can simply ignore all the risk areas I've posted? No. Most of the reviews (perhaps 80%) were conducted on teams with fewer than 5 people. What this does mean is that with only one or a few developers you can get away with a lot and only have a few red flag risk areas. If you are lucky you will survive them, and if you are unlucky they will bite you. Hard. But most of the time you will slide by well enough that you will work nights, weekends, and have no social life -- but you will still have a job.
But, if you have more than 5 people you probably have to do most or even all of the process activities listed in these risk areas. If you blow off using a rigorous process, it is pretty likely you will fail. Probably you will fail spectacularly.
At least this is what I have observed doing 95 reviews over 10 years in industry. Your mileage may vary.