Greets.
Sorry, I just saw your post. I can't comment on your TS19 questions as I remain a TANE user, and am currently applying superelevation (SE) to a pretty curvy route. Here are a couple of observations that may help you:
First, I don't apply SE to the endpoints of straight sections. If I have a curve between two straightened sections without a vertex in it I add one at the midpoint ("summit") of the curved section and apply the SE to that vertex only, as you allude to. On long sweeping curves, I have found it necessary to add more vertexes, preferably keeping the linear distance between them down to about 100-120 meters (300-360 feet in archaic nonmetric units), BUT BE CERTAIN TO DIVIDE THE CURVE INTO EQUAL DISTANCES BETWEEN VERTEXES, OR THE SE GEOMETRY WILL NOT BE CONSISTENT.
Be aware that when adding multiple vertexes in a curve, doing so will often affect the track's horizontal and vertical alignments, so I use markers to plot where the unvertexed curve was beforehand, and return it to that geometry after adding in the new vertexes.
As to trackbed scenery or terrain, I have found that in curves where the SE is calculated by Trainz to be high, most types of track will required upward adjustments to the underlying terrain in order to cover the "floating" high side of the track mesh. This takes extra time and effort.
Applying SE to an existing route is tedious and repetitive, but I feel the result is worthwhile personally. And like anything else, you do get faster at it as you go. If you want a comparative example of the method I am attempting to explain here, download my DSEPR01 route now, then Version 2 in a few weeks when I release it and check how the trackage has changed in the longer curves along the open countryside at either end of the route.
Another timesaving tip I can offer is this: Take the time to set up a spreadsheet to do the maths to work out your P1 figure. My spreadsheet gives me the P1 for any speed between 1 and 350 km/h by simply scrolling down to that speed's line in the sheet and reading it. The P2 figure sets the maximum SE angle (in radians just to make it easy - thanks N3V), so will be the same across the entire route as you no doubt know already.
HTH
A71