I see your thoughts but you need to think more openly. Easiest is to give it a try and you will see. (6/6 now)
The broad strategy is to deny Terran their return on investments on the low ground when their economy is least established. If they spend early gas on income generation and protection (2 gas walls, con yard), every bit lost is a big hurt when they return to the high ground.
Re spawners: The traditional route of more spawners via a supply upgrade, some drones, construction, units spawning, is all time given to the opponent to strengthen their position and get that ROI. So upgrading existing spawners is by far the better choice to hasten attack pressure.
Re: tanklings are hardy and require more energy to kill. They become enhanced with the +1 armor upgrade. We're not building a lot of their structures because it ties up too much minerals and supply and I haven't found it beneficial to build more tankling spawners either.
Small aside, I have noticed that the strikling and tankling combo is good for dealing with reapers. By chance, they auto attack the tankling while the strikling closes.
Re infestors: You can happily drop the artillery at the rear and transfuse the baby spine, because while he's dodging shots and shooting zerglings you can pepper the walls to regain energy. You can build more infestors too.
There is a lot of time in this moment for Zerg. You can move the creep up for the hydralisks, drop a spine crawler, and wack their tech lab. Whatever you like.They simply cannot field a strong defense to protect every wall of their base. In fact the greatest help comes from the other side of the map by tech lab power ups or troops.
Re mineral tower: All three players are never again a threat to those mineral towers so its a non-issue.
Sentiments: Yes I share them. If you know you can win by doing a particular strategy it feels wrong to ruin the fun for 3 others .. but the better player C is the more enjoyable the toing and froing becomes