Welcome to the 'bolt, John C. Don't take this the wrong way, but the easiest way to accomplish all the items on your list is to trade it for a halfton. The 3/4 ton shares NO parts with the halfton below the frame; springs, shackles, hubs, brakes, drums, etc. are all larger. To change to 6 or even 5 lugs on the front, you can either alter your existing drums/hubs for new lugs or go IFS. On the rear end, only an axle swap will change the bolt pattern.
When set up properly, the stock steering should be safe, smooth and easy. Get a shop manual and, if necessary, a rebuild kit. If you're running wide tires it makes steering effort much greater, and you may want to look at
this . I also found
these links most useful, just remember that some of the info doesn't apply to your 3/4 ton.
The most cost effective way to make it safe is to restore. Otherwise, you're going to have to replace all the 3/4T parts, either with 1/2T or IFS. As for disc brakes,
this guy describes the only plan I have heard of to keep your 3/4T straightaxle; otherwise, you're going to have to do an IFS which takes care of the steering, brakes and safety at once.
Good luck.
