I've unpacked pak001.pk4 and changed the dev files to make myself some weapon and monster mods. I've even repacked the files using PK4Scape. I've even downloaded single player mods. Nothing is working and I'm working with the latest version of Quake 4 (1.4.2 at the time of this post). I have access to my old windows xp pro computer with the windows version of Quake 4 on it, but I'd really like to be playing these mods on my iMac with Quake 4. I've been pulling my hair out over this since Quake 4 first came out. I've been able to make single player mods work fine for my copy of Doom 3 but nothing has worked in scripting mods for Quake 4.

Make sure the mod is for q4 1.4.2 and the mod folder has to be in the quake 4 folder.

already did that. I even scripted my own changes but the game freezes up and gives me the console as soon as I try to play a map. I don't know what they changed between Doom 3 and Quake 4 maybe I missed something in the scripting or something. Console gives the error of playerview not found even with the full pk4 still part of my changed scripts to the weapons. I don't know if the patched version of Doom 3 will give me this problem like Quake 4 is and I'd hate to go back to scripting for Doom 3. I just want to make mods that I can play offline and enjoy.

You could try this:
backup q4base/Quake4Config.cfg
delete q4base/Quake4Config.cfg
retry the mod.