Will a high quality preamp really make a difference in sound?? Also speaker cable

Additional processing will not necessarily negatively affect the signal. This is a misconception. And at the very least, positives may outweigh negatives.

More on amplification, definitely more. Unless the very top level where it might get equal, I don't know. Give any good speakers a signal and they will sing.

Common audiophile wisdom - active preamplifier is extremely important.

Speaker cables, like everything else, are important too. My speaker cables cost new or used as much as my speakers. Perhaps I overdid it a little but I haven't had to replace them in 25 years, and my system now sounds incomparably better than 25 years ago with the same speakers and cables. But it's a modest system, both speakers and speaker cables cost $1500 new 25 years ago.