I agree with alot of what your saying but I would say you dont explain alot to the laymen to understand the acronyms your using.
NAT = Network address translation, each node on the internet has an address which is xxx.xxx.xxx.xxx which is often refered to by a name e.g.
www.bbc.co.uk (this name known as the ip address is looked up and the real address is always used).
With a router (or ADSL modem/router) that permforms NAT it splits the networks it operates on (local and internet) into two different address ranges - one private and one public.
The whole point of a NAT router is that your private machine may open a connection over the internet which the router will route your outbound traffic to and the router will also know because your talking to that source that any inbound traffic from that remote address needs to be translated to the local address and forwarded to you (this can be gone into much more deeply on port levels but this explanation is sufficient).
I dont agree with the rant on software developers not coding for non administrative accounts. Quite rightly so the operating systems have been restricting what we can do so for some operations we have been required to ask users to login under administrative actions to perform these things. The problem actually is that the end user see's this as an irritation and rather than suffer the account changes decides to just run as administrator all the time for a simple life - which then creates the security risk. It is not something the software developer can either code for, cater for and allow for - its just human nature.
The changes in vista were to give us software developers an avenue to allow the user to temporarily go into administrative mode to perform these functions - which is not dissimilar in linux to drop into superuser etc.
I would say before laying blame on the developer - fully assess and understand the constraints they are working within.
Regards
Jof
p.s. TCP is the transmission control protocol - above that is either IP or UDP it is not TCP or UDP as UDP is over TCP.