Need help multiple error codes

[MrJonAdams]

Hi I'm brand new here but I've been a frequent snooper but I've finally come to a problem I can't find discussed before. The other day while driving my check airbag light came on it comes and goes but never stays for more than a minute. So thinking it had to be a sensor I went to oriellys and had my error codes checked only to reveal much more problems than I expected. The codes were: p0237(which I have had sinse I replaced my fuel pump so I think it's just faulty especially because the fuel gauge hasn't been right either i got another replacment I haven't had the time to install though),P0480,P0463,P0455,P0332,P0327,C0040,C0035,U1041, I think it pulled up 14 total codes but many were duplicates I think he said. my truck a SCSB 4.8 with the work trim 2005 model and just under 145,000 miles The oriellys guy suggested it may be a failing ECU and after a little research I'm thinking he may be right but I'd just like to see if any of y'all might have some ideas. Also the lights flicker like they did before I replaced my alternator and the voltage jumps around on the needle like crazy but I think I may have just picked up another faulty part butluckily that can be replaced under warranty. Other than the flickering lights the truck doesnt show any obvious signs of problems. Any and all help will be greatly appreciated needless to say it ruined my evening yesterday hah