I basically came here to say the same, regarding the FET: Most likely there are parts with the same form factor but much lower resistance (both switching and fu

I basically came here to say the same, regarding the FET: Most likely there are parts with the same form factor but much lower resistance (both switching and fully on), which don't have that problem. The price-difference might matter in mass production, but for a repair at home, I don't see a reason to go with a cheap part. Decreasing the turn on/off time might also be a good idea to prevent future repairs (nice spot!).