Diesel Bombers - Opinions on truck purchase

Came across a truck I'm thinking about trading my 93 crew cab in for..
Specs: 2005 f250 crew cab long bed 4x4. 6.0 powerstroke with a six speed manual transmission. It's a one owner vehicle with 150,000 miles. It appears to be bone stock. Out the door, with my trade in the price will be around $9000. Kbb value shows $16000. The body is in excellent condition, no dents or rust anywhere. The frame, rad support and under body are totally rust free. Only rust is on the ends of the bed cross members at the wheel wells.
I got the car fax and shows its been a PA truck it's whole life, with one owner. No recalls came back, title is clear, and no major work was shown to be done. No other service records available.
I like the truck, love it. It'll be a great replacement for my old f350. My problem is obviously the motor... To many horror stories. So I want the experts who have these use them and work them to tell me what they think.
Some key things I seen when I checked it out: clutch is a little bit soft, feels like air in the lines. Hoping new fluid and bleed will solve it. Oil pan gasket looks to be leaking. Can it be replaced without lifting motor? The truck spools slowly. It will spool slow up until about maybe 3k and build up psi and blast off like a bat out of hell. A little bit of black smoke when it finally takes off. Any opinions on this? I'm thinking egr needs cleaned? What do you think. These are the only things I noticed while on test drive. Otherwise it seemed great. Any help would be awesome. It does need a wheel seal and tierod for inspection next year if I remember correctly. But those don't pertain to the motor.

If I get it I want to change oil (currently at correct level with old oil so no one is trying to hide anything), would like to replace fuel filters, flush antifreeze, clean egr, fix clutch and replace air filter. I can't think of anything else right now. Will this help with the slow spool? Anything else I should take care of immediately?

Is this worth it? Should I get it? I want something I can have for a very long time.. What are your opinions?