It has the Peugeot BA10/5. These are known for being weak
Floors rust, bedsides rust, frame rusts where to front of the leaf spring mounts, sometimes rockers and cab corners rust.
Swap in the 8.25 unless it has a D44 (you say it doesn’t)
I can’t say whether or not you will rub, I clear 31s with about 2.5 inches of front lift without rub. Rubbing will depend on the wheel backspacing.
Can’t say about SOA either.
How easy it will be to learn manual on depends on the axle gearing. My guess is you have 3.07s, so it won’t be super easy.
All that being said, you should get it as long as it is not SUPER rusty. Odds are it will have rusty floors and maybe bedsides. Also, rust can be fixed relatively easily if you can weld.