His presentation really just seems like his opinion and 'general mis-info' that is found on the internet. No hard evidence or testing. I don't buy it.
Cutting Coil Springs
Here is a good explanation on cutting springs to lower-
http://www.eatondetroitspring.com/cutting-coil-springs/
"The first thing you need to know is that cutting a coil spring will not only lower the vehicle, but it will also stiffen the spring making the ride and handling a bit firmer. But this is a good thing because lowering a vehicle reduces the amount of suspension travel. A stiffer spring will help reduce bottoming out."
A 200lb/in spring with 10 coils, 1" movement requires 200lbs and each coil moves 0.1" with 200 lbs. If this coil is cut in half, to 5 coils, that same 1" movement will require 0.2"/coil compression and that will require 400 lbs for 1" compression. So now the same spring when cut is rated at 400lb/in. The spring material/thickness is the same, but the spring rate is different.
Spacers
Sure spacers move the wheel out, but his recommendation of wider wheels also moves the wheel out and 'increases' the force/leverage on the wheel bearings. The real question is how much is this increase? Actual tested value and does this increase force really cause wheel bearings to fail? I've had more wheel bearings fail not using spacers than with spacers.
Increase Camber
Yes to a degree this does help some cars keep the tire in contact with the road in turning. Done extremely for 'show car' just looks dumb.
Sway Bars
They can improve and worsen understeer and oversteer. Most manufactures use smaller diameter sway bars for 'comfort' and use larger bars for performance. Here on the E9x chassis, 328/335/M3 all use increasing thicker sway bars. Don't go overboard. Again not using a 2" sway bar. Testing not opinion.
Spring Compressors/Expanders/spacers/cups
All attempt to change spring length and affect ride height. Many times there are no readily available springs with different lengths, so this can make minor adjustments in spring length. Those bolt on coil compressors are a little hockey.
Just take what you read or hear on the internet with a grain of salt and not as gospel truth. All cars are different and making general statements without being specific is of little value.