[Allworth]

I would have started by replacing a MAF sensor, then I would have called forced DPF regeneration. If it works, it works. I had to do a software run for DPF at 120k miles, I had an error saying 'end of life reached' for DPF, but in fact is still in a good condition.
Running with this error for a very long time means no regeneration is taking place and is likely to result in a blockage sooner or later, so your worries are valid.
It seems error 1,2,4 are linked together and could have been sorted by replacing MAF sensor. 3 is a bad Glow plug which only affects cold starts and start/stop system. 4 and 5 looks like DPF errors.