I agree with all points although on point 5 I think some relatively inexpensive trousers can be decently cut (as long as the wearer is of 'average' proportions). I'm thinking of those sold by Cordings for example which could be called 'traditional' in cut. That said - the trousers I have made do have a slightly higher waist than average & look the better for it.

If I had to pick, I'd place more importance on a well cut jacket than the trousers (within reason) but in many office environments jackets aren't worn so trousers take centre stage - perhaps your suggestion that it's better to skimp on jackets than trousers makes more sense.
   

A few of my male colleagues on Fridays wear what I image must be stretch denim trousers - great on women but not a stylish thing for men. 

As regards socks I've sadly not found that expensive ones last very much longer than cheap ones but they do generally feel nicer - the main thing is - whatever they cost they should be full length (over the calf) as you say.

Regards
RFS

Number three is a particularly widespread phenomenon -- especially for men with a prominent tummy. They have been sold on the idea that pleated pants are slimming, and they wear them on their hips, ie. under the overhanging tummy. This in turn causes the pleats to balloon, creating the unfortunate impression that the wearer is experiencing permanent priapism.

3 (b) is the same pants, worn on the hips, and thus too long in the legs, resulting on a puddle of fabric above the shoe.  In extreme cases, the hems/cuffs are ragged from being stepped on.

when you think about it, it is the bottom half of a man's outfit that is usually a disaster. The trousers, socks and shoes are usually awful; far less men pay attention to the bottom half.