You can get oil dye from any major parts store for under $5. The crankcase is just a common term for where the crankshaft resides, part of which is the oilpan. Just pour it into where you add oil.
This what the rack and pinion looks like. You can buy one from any of the major parts stores, they run right at $250 at autozone:
As far as driving long distances, there simply is no way for someone who hasnt physically inspected the vehicle to know how safe or reliable it is to drive for long distances.
A severe oil leak can of course cause engine damage if oil level isnt constantly checked.
If steering is loose due to worn rack and pinion, then it can be dangerous to drive. If it is leaking power steering fluid, you might be ok, unless you dont keep the p/s fluid topped off.
As I said, without physically inspecting the vehicle, I cannot accurately tell you if it is safe to drive a long distance or not. No one can without physically inspecting it