On a mopar uper contorl arm, caster/camber range is limited by the range of adjustment available in the bushings. you can only twist them so far befor eyou run out of adjustment, and often to get the desired camber you have to give up caster. Building additional caster in to teh arm allows additional adjustment.
You don't need an aftermarket suspension to get good handling, but many people think you do. One big advantage of aftermaket set ups is that they typically drop 100# off the nose of the car, have a broader range of adjustment, and can rapidly and easily change spring rates.
Manual steering boxes do require more effort to operate at low speed, especially if you use more modern alignment specs. Typically a larger diameter wheel does not make a big difference in effort, but the additional width that typically accompanies those diameters will increase the required effort.
You can drop a mopar a fair amount, but turning down the bars to lower the car will impact the range of adjustment you have in the alignment effort. It also is contingent upon what size bars you decide to run too as bigger bars will need less travel than smaller bars and can be turned down lower.
If you will eventually swap to an aftermarket set up, you may not want to drop too much coin in making the stock stuff work good. But, like a lot of things in life, good is a somewhat subjective term that only you can qualify.
