This Almost RUINED My Project Car! 

Finding cracks has to be one the worst feelings. Especially when you did the welding yourself. That experience is something that can't be learned in a classroom. Realistically it doesn't look all that bad. One thing you can do to improve durability on thin material is to leave a raised weld bead to spread the load across the joint witout overheating that causes it to become brittle. Keep it up. I still want to see the thing going off road.

Wow that is quite the project It’ll take a long time to get it dialed in but super cool

I checked this video out, because of your amazing tool organizer/3Dprint video. I run a welding, code & inspection company. Started the business after years of traveling, as a Journeyman Pipefitter/Welder. I don't watch welding vids on YT or give unsolicited advice in the comments. I find it unprofessional and I'd essentially be doing my job, in my free time... I could point out specifics, as to what I think caused the weld failer and how to improve, but I'm sure you've been told that by someone already. I think it's more beneficial to just encourage a fellow welding peer. It takes a lot to put your work out there and you deserve respect for trying your best at learning a new skill. Keep practicing and find a solid mentor, if possible. Take care.

I can relate with the fear. Any failure burns into your mind and creates doubt. My father in law passed his pride and joy down to us. It's a 96 f250 power stroke with 175,000 miles. The first issue was the transmission, which would go into limp mode... I ended up getting it rebuilt. After the rebuild, it jumped and shimmied in reverse. Took it back and had it fixed immediately. 2 weeks later, it didn't move... sent back again... filter had fallen into pan. It now works well. On a short trip on the highway, it just died. The fuel bowl heater had broken, shorted and blew a 30A fuse. I replaced that and cleaned the fuel bowl, which had clogged the drain as well. The alternator died, but Dad had a new one in the tool box, so I replaced it. It was still cranking slowly, so I replaced both batteries... still slow, so I replaced the starter. Another short trip exposed a fuel tank leak, so a new rear tank went in next. The tires were 10 years old, so I replaced with some Cooper Discoverer AT3 10 plys. Recently, the truck died again. I replaced the camshaft position sensor, still ran rough, so I replaced the Injection Control Pressure sensor with an eBay "Ford" sensor that ended up being a China part... it immediately leaked right out of the package. Went to dealer and paid $150 for the real deal. Runs great now. I have replaced all the fluids, including oil, diffs, t case, coolant etc. I am about to take it on a real trip.. about 900 miles each way. I have confidence in the new parts, but just wondering what may rear it's ugly head.

I would certainly hope your partner would have at least given tips, tricks and helped guide you in a few places? Hopefully? Cant go "Nah fam thats bitchstuff" and then turn around and go "now figure it out" hahaha X3