Sharing iTunes files between PC & Mac?

I use iTunes on both a PC (in my home office), and Mac (in my listening room, with Mac laptop connected to my DAC). Currently I have my music collection ripped to Apple Lossless and saved on an external hard drive connected by USB to my PC. I have created lots of playlists using my PC version of iTunes.

Currently, when I want to hear these files in my listening room, I open iTunes in my PC, then open iTunes on my Mac laptop in my listening room and connect wirelessly to my PC's itunes library through the iTunes "Shared" mode.

This seems to work fine but I have 3 questions:

1) Am I getting the same quality when listening to my mac/stereo when accessing my PC's shared iTunes library as I would get if I had those same music files wired directly to my Mac on an external hard drive? And would that be the same quality as accessing the hard drive from both PC and Mac on a wireless network?

2) Can I unplug a hard drive of Apple Lossless files from a PC and plug them into a Mac to use with Mac iTunes, and go back and forth without any problems?

3) Can I share iTunes metadata, such as playlists, ratings, etc., by creating them on iTunes for PC, saving them to an external hard drive, and accessing those files from the hard drive to my Mac? In other words will Mac iTunes read the iTunes Music Library (metadata) folder created using a PC?