Endless discussions in Gemara and rishonim center around questions of phraseology.
The type of phraseology questions that I am talking about are those of why he used word X and not word Y. Those types of discusions are rarely in the gemara/rishonim. I can think of a few examples but they are not common at all.
Because, he explains- he wrote with Ruach hakodesh! (or something to the effect of ‘divinely inspired’ – don’t remember exact lashon).
I also write with ruach hakodesh.
What do all the quotes about improper application of iyun skills have to do with this discussion?
Welcome to the CR.
but a cursory reading of many complicated sugyos would not qualify for ‘decently well’.
I didn’t say to skim it. You need to have basic havana of the shakla v’tarya.
That’s not learning tosafos.
True. It is studying tosfos. To learn tosfos makes no sense grammatically.
which you retain much better than randomly memorizing gemoros.
False. It’s not ‘random memorization’, and people do retain it better.