[special-K]

I think it's a 6.2. Is this a post-87 C/K model,or an R/V model (square body). There were never any turbo charged 6.2s. They bumped the naturally aspired 6.2 up to 6.5 when the 6.5 turbo came out. These are all the same motor with the 6.5s just being a larger bore. These trucks will run without a lift pump (fuel pump),but it's hard on the injector pump.The purpose is to bring the fuel up from the tank to the IP so all the IP has to do is pump fuel to the injectors. The lift pump primes the IP. The 6.5s with electric lift pump use a block-off plate at the mechanical lift pump location. So,you could use one of those and run an electric one. But,I've never had an issue with the 6.2 mechanical pump. I see no benefit since the pump doesn't actually run the engine and they aren't know to be problematic.
Fuel gelling is a fuel problem that effects any diesel when the fuel gets cold enough,no matter what motor or what the fuel system equipment it runs. Fuel additives help prevent gelling and so does a full tank. It's just like water freezing. The deeper and larger the basin,the longer it takes to freeze. It has to be damn cold for diesel to gel,like low teen for a while or single digits. I have seldom used additive,only a few times when temps were going to single digits...and I ran out that night and topped it off.
Dirty fuel is handled by the fuel filter. Fuel filters are very important players on a diesel fuel system.
No problem removing the turbo,since they are both the same engine. The turbo is good for 60 more hp. The 92/93 mechanical injected 6.5TDs use the same IP as the 6.2,the Stanadyne DB2. They're a very reliable pump