Allowed third-Party tools usage (Mod'ifications)

Any mod that affects gameplay Indirectly, like Optifine (Helps in FPS) and randommobs
Any mods that affects gameplay directly, without affecting other players or giving yourself huge advantange (Mods that move items in your inv, like InvTweak)
Any mods, like CTM (Conected Textures mod, comes in optifine) that affects blocks or texture packs.

EDIT: There may be other allowed mods, but most are Hacking clients that arent allowed, Like Nodus.

So does that mean all the mods that you listed in the FIRST passage not the "EDIT:" part can be used right? But you said some will crash your minecraft and mojang cannot help. Could you list some of those?

Thanks
Dmah

Possible crashes are, depending on the mods you use, could be due to incompatibility, ID conflicts, Incorrect version of mod, Incorrect version of minecraft, ect.
For example, You cant use MCpatcher + Optifine, they both will crash, they provide the same HD features for texture packages, plus causing a crash.
Sometimes you could have Aether and then Tale Of Kingdoms mod, but aether has a block that has the same ID value that the tale of kingdom mod does. If this is the case, when you start minecraft OR start a world, you will crash.

Sometimes, you require others mod for a mod to work. You cannot use Macro Keybind Mod without modloader.

If you ever crash or have problems with a mod or Third-Party tool, (Third party tools are the current: Modifiers, [mods], World changer, Inventory edit outside of minecraft, ect, like MCedit, generally NOT made by mojang) will not be supported by mojang and not affiliated with them. In the case of crashing, you can not go to mojang and mail them and say " i crashed because i had optifine and mcpatcher"
They will simply ignore you.
Instead, go to the mod thread you got the mod, optifine OR mcpatcher and post your detailed crash report.[[Only admins are allowed to see this link]] then await your fix.I can also help with some mods.

Wow that's a good amount of info thanks a lot pedro I appreciate your help and the time you took to write this knowledge about this stuff.
Does MCedit have anything to do with MCskinEdit?

Sincerely,
Dmah

Dmah wrote:

Does MCedit have anything to do with MCskinEdit?

Depends. MCedit is a world editor and MCskinEdit is a skin editor.
They shouldnt have anything to do, but if they require both of themselves to work in some feature, they could, like adding any texture to a mob so it always appears that. (that doesnts exist, but it's a example)

No i just used it to make skins i think u saw my customed skin or brood did idk it was when helgen was still in the old map