I can't answer all of your questions, but I'll say what I can.

2.) where do the custom results screen go (in the pf folder)?

The results screen images go in pf\Menu\common\char_bust_tex. They are .brres files and are titled "MenSelChrFaceBxxx.brres". Each character has a different number.

3.) can you refer me to a naming guide for the stages?

I believe that the stages are named in the link I posted earlier.

4.) does each costume for each fighter have its own attacks pac? If so how do you name that?

I may be wrong here (this is based purely off of speculation and observation), but I believe that a .pac file changes the moveset/bone structure of a character, and a .pcs changes the skin of the character. So I think that if you have one .pac file, it applies to all of the characters costumes. Again, I could be wrong.

5.) when a song plays on brawl there is a rectangle with the name of the song in it. If I put my own songs in can I edit the name that goes in that box?

I am 99% sure that this cannot be changed.

Ah, that did the trick.

Thanks, that was really bugging me. 

1.) What are the names of the folders in the pac files to change the character icons and portraits in and out of battle?

In sc_selcharacter_en, there are four important folders, the way I see it. char_bust_tex_lz77 is where you change your CSPs - the portrait of the character that shows up on the bottom of the character select screen. Each character is assigned a number that applies to each of the folders; for example, Cpt. Falcon is 9. MiscData[30] > Textures(NW4R) contains the characters' names that show up on the bottom of the character select screen, on top of the CSPs, as well as the character logos that appear on the character select screen. MiscData[70] > Textures(NW4R) has all of the character select icons, the little boxes that you use to select a character on the character select screen. It also has the names that appear over the icons. MiscData[90] > Textures(NW4R) has the little heads that appear in various places throughout the game to indicate which character is going to appear next. These are the most important folders for the mundane hacker, I believe.

For the in battle portrait, you need to find the InfFacexxx.brres that corresponds with each character and edit it to your liking. For example InfFace091.brres is Cpt. Falcon's normal color battle portrait. The InfFacexxx.brres files go into pf > Info > potrite .

2.) Does each costume have its own name on screen? Like if I have two different textures on marth can I have the names marth, roy, and ichigo all on that one character when you change the costume?

Unfortunately, no, each character can have only one name. However, like mentioned above, you can change their CSPs to reflect the different costumes.

3.) Finally where are the folders in the pac files for the loading screen, the sound effects and music, the on screen words (like 3,2,1 go and game, and would you like to connect to wifi etc) and the results screen. 

As far as I know, sound effects can only be changed when using Riivolution. I use Gecko OS, so I can't help you there. Music goes in the pf > sound > btrsm folder. The songs need to be in .btrsm format, and need to be renamed according to which music slot on which stage you want them to play on. I will include a link at the bottom that has a list of the music names. Most of the things you suggested are in the MiscData[30] > Textures(N4WR) file.

http://brawlhacks.wikia.com/wiki/The_File_Placing_and_Naming_Guide

First things first where does each pac file for brawl box go? I think I have them all but Im not sure exactly which ones go where. I was able to put a few in but alot are still not in yet.

Can you specify?

Second in my folders for the fighters nothing is in them is that okay? Do only the hacked characters go in them? Same with the stages?

Yup, that's fine. It'll only change the characters if it finds something it can USE to change them.

When you want to save, choose "Save As...". Name it whatever you want, and then it should take you to the Save Configuration window. Under Bit Depth, mark off 32-bit.

Finally, someone I can help!

I was having the same problem earlier. What program are you using to edit photos? Make sure to save your photo at 32 bits, and make sure that it is the correct size.

You guys probably get a million questions like this, but I think I've exhausted all my other options.

I know that the limit for sc_selmap.pac is 1.14mb, and the one that I have is sitting at an easy 1.13. Whenever I change any of the pictures (including names), the size shoots up to ~2.3mb. I've tried all the tips and tricks (well, only indexing and posterizing), and have gotten my replacement images down to ~one half the size of the originals. But the size still goes up. What am I doing wrong? Should I just drop it?