The Stack Exchange sites forbid shopping Questions. So Question #1 is OT anywhere.
Question #2 is argumentative at best. Cables are rated for a particular speed and competitors would love to find a manufacture making faulty cables. Basically it never happens.
What does happen (a lot) is poor installation. I'd dare say the vast majority of installers do not know the tolerances of Ethernet cable, nor are they particularly careful while installing it. But this usually results in cables that "work" so nobody cares.
To answer your real question, yes there are cable testers which can rate the quality of a run. They are very expensive and you'll almost certainly choke on the price. Fluke (whom I personally recommend, probably the world leader in prosumer and mid-business grade test equipment) makes a Copper Cable Certifier, the DTX-1200 that will rate/certify cables. It costs about $8000 as of writing this.
Otherwise simply plugging two Gigabit capable NICs into each end and seeing what speed they auto-negotiate should give you a good idea of the cable's quality (though this is far from foolproof).
To answer the Question here; Server Fault would have been the most appropriate for your Questions, though it probably would have still been closed as OT or NC because of how they're worded. The SE sites are not a forum, you really can't treat them like one or your Questions will be close every time.