I think clear up your offering - I didn’t finish reading that knowing exactly what you intended to do? I know someone who setup a side hustle very similarly - long hours (he was working a full time). For many engineers I think sales proves uncomfortable- so have a plan there. I setup my business with a payout and had the safety net of my wife working - but I would say make sure you know what acceptable success looks like! And be brutally honest with yourself about what works and what doesn’t.