Yeah, I looked up those threads prior to writing, but forgot to go back and link & do some copy/paste on some of the gems.
Dropped in your spell sequencing example, something that definitely needed illustration
As far as action economy, I've been looking for spells such as Light of X, where it can be pre-cast and expended later.
Also perhaps need to find some swift action feats that are worth it.
Typically my players have been pretty good at grabbing magic items with swift action activates, so it hasn't been on my mind too much about expending multiple spells per round, as per Quicken, swift action spells or other methods.
Heighten can certainly lead to some circumventions, of which I try to doc in the house rules section.
Also reminds me I need to make mention of Shadowcraft Mage. Another case where effectively having 1000 spells known all day isn't so good.