Another idea would be to pick a technology, say renewable energy, and go ...
Please not that. It's completely polarised between the 98% dilettantes and the 2% that know ohm's law, it's been completely overexposured in the media, and too much politicians are stuck between budget cuts and easy media attention. And they're scared about everything due to being "generalist"
I made the decision to stop talking to outsiders about renewable, drones and 3d printers, because after 3 sentences all I hear is some false representation of what was falsely stated on the news.
It's not the degree of stupidness that embarrases me, it's the 'volume' of stupidness. Before, I politely endured their words, carefully trying to send it to another topic, but everytime it ended up like suddenly everybody at the table had to say their words about it.
You did debunk the solaroads story in a great specific and detailed way, no need for more. The greenbelievers will keep on disliking or blocking your video, the people in the sector knew the thruth before 2004.
No one has any idea for topics? 
One thing I would like to see, is a series of videos that show
the huge difference between a hobby project and a product realisation.
As you showed before, you quickly run up to EMC and machine, electrical, safety regulations but there must be a way to illustrate both paths.
Many are stuck at the 'blinking led' level, but also at the breadboard or prototype level.
There's also
a big difference between making something for yourself and make it work for others too.
Maybe coach people with a prototype to realise their product selling?
No one has any idea for topics? 
Where's the Dave that said: Don't fucking tell me what to do.
If you have an idea, do it yourself... Wgroahr.
:-) :-) :-)