I also took the plunge on the DIY kits. I have slightly more soldering experience having also done the NESRGB mod, but certainly not with such small SMD components.
Out of curiosity, did you know about https://www.niksula.hut.fi/~mhiienka/ossc/diy-v1.5/assembly_tips.txt? I’ve found his recommendation for 300C and connecting opposite legs on the ICs first (to achieve good alignment) before drag soldering the other 2 rows to be excellent advice. I also struggled to remove solder from IC pins and my side to side motion resulted in more than one bent pin that was tedious to fix. I found it was easier to control the flow of solder to the legs by using a very fine tip and only putting enough solder on the tip to go a 4-6 pins at a time. Maybe with more practice I could have used a larger tip and done the whole row in one drag like he recommends.
I was able to get the board fully assembled, but discovered that all but one of my voltage regulators have a pin with an incorrect connection to ground. Hopefully I just have a small bridge on the ICs that needs to be cleaned up as I’m still very new to the art of diagnosing malfunctioning circuits.
Best of luck with your second attempt.