Diesel Bombers - Powerstroke Questions and concerns

Hey guys. I am young and new to the diesel world. I'm seeking advice from people who owned a diesel longer then I have. I purchased my truck (2004 F350 stock w/225k Miles still running strong) wrecked. Since I owned the truck for 7 months and have dropped 6k into it. I have many concerns about my truck staying healthy and want to know what I can do to check so I can keep me from destroying the truck or have a very expensive break down like the EGR cooler clogging. I understand the maintenance and I'm always on top of it. My concern is that I am about to be hauling trailers across country for the first time and I am afraid of a break down. What are some tests I can do at home to make sure I do not have any parts about to fail on me. I do not have a egr delete yet and that is one concern. But I will be putting one on after I start making money with truck. I Also I ran my truck out of fuel (gas gauge stuck on full) but I felt myself loosing power so i shut truck off(I am very very ashamed of myself) and also diesel gelled up on me once this winter. I recently had 4 injectors replaced on drivers side before I ran out of fuel a week ago. mechanic said I have 2 injectors with a very small miss but nothing major yet. So my question is, What can I look for (like pulling EGR and checking it, cleaning turbo ect.) And if I have a small missing on 2 injectors, will this cause my engine to hydrolock? I am purchasing gauges tonight from glowshift. Will gauges answer any questions? I was told there is head studs, but I dont know how to check to make sure. So What is some advice you guys can give me with your experience with the 6.0 powerstroke. I Do not want to be left dead on the side of the road and want to learn what to check for. Can you guys help out a new diesel owner and what you guys would do in my position. I will appreciate any advice. Thank you Guys!!!!:argh: