UPDATE ON SMUGGLING VS. TRADING (with a warning)
I have promised to give an update on smuggling.
as described in the OP, i have found that trading and smuggling is neatly balanced on a basic level.
further testing has shown me results, that it is either bugged with consitent triggers (very possible with anything illegal trade), or gets pretty unbalanced if you combine several parameters in a certain way, which woudn't be the case in daily play, or both. i have therefore filed a ticket for a potential exploit, and won't share my tests till it is patched. please don't pm me to ask how-to.
instead of it, to the best of my current knowledge:
if you suspect, that you are under a smuggling attack (which isn't easy to spot in the first place, as random traffic or running missions for all other factions for exampel can have very similar effects)
1. do a few maximum influence gaining trading runs as you can construct from the OP: as many different profitable commodities as possible, with 700 cr/t profit or more if possible, but not necessarily.
2. do not try a trade war, instead of it use all other ways to gain influence additionally at once.
3. redeem bounties as often as possible (number of redeems, not CR value!).
4. cash in up to 11-20 mio in exploration data daily.
5. run missions.
6. prefer civil unrest above boom.
7. trigger a war/civil war in any of your system.
8. if nothing else helps, trigger a lockdown.
good luck!