There's no way to play D2 with a No-CD patch unless you copy some files off the CD first. There are some games where this isn't so, but with Diablo II it is. If the game loads very slow, and stuff copies over very slow, either your CD is burned weird or your drive is slow.
And, just a little tip .. CD-R/RW drives were built to burn CDs, with the laser going in one slow motion. Using them as CD-ROM drives really wears them down. Trust me, I'm on my third CD-RW because of that.