Forge Mod minecraft for magic launcher?

I'm currently in the 1.7.4 version of minecraft and I'm trying to install the forge mod for magic launcher, but when I try installing it, I get an error saying "you need to run 1.7.2 manually at least once." can you tell me, step - step, what this means and how do I run that version? I'm new to modding on minecraft

Added (1). can someone explain this

Run Minecraft > Patch it to 1.7."TWO" not 3 not 4 > Start Game > Close MC > Install it

We think your minecraft may be modde error?

My minecraft says ''we think your minecraft may be modded, and as such we can't accept this crash report.etc''can anybody tell me how to fix this error? I DON't'T USE MODS, and i instaled about 6 minecraft from different sites, all of them give me same error, please help me fix this problem.
P.S: my english is prety bad so don't judge me.

Added (1). i din't bought the game

What Minecraft Mod Is This?

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Above is a link to a Youtube Video. In this video, he has some mod that shows players' health in the bottom right corner of his screen. What is this mod?

How are programs developed?

I'm in High School and I would say decent at the actual coding of programs themselves, I've made a number of tools that lets say "edit" video gamesaves. However when I see other people posting their own programs and such like a mod for Minecraft I notice there's sort of a standard to how they are presented. Things like current version, change logs ect. But I'm not sure how to go about doing that kind of stuff.

My question is after I've written the program I want to share what do I do next besides just uploading it?

Multiple mods for minecraft 1.7.4?

How do I use multiple mods for Minecraft 1.7.4 (or any version for that mater that uses the new launcher) since I want to use XRay mod and OptiFine at the same time (I run Minecraft on Windows 7).
Please be as detailed as possible

Why does my minecraft close?

Simply this:
1. I'm modding it for 1.6.4
2. I already have 100+ mods so i get the idea of how to do it.
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The problem is when i add certain mods my minecraft crashes.
Its not really a crash it just runs, goes to the "MOJANG" screen,
then closes. No error, no "your minecraft has crashed. Nothing