I have already asked around but as I′m not so familiar with game altering, I decided to come on here and ask.

As the headline says, I′d like to reduce gun spread on the minigun. I′d also like to increase its rate of fire. As it is vanilla, the minigun has the rate of fire like any other automatic gun, only difference is its mag size. Real miniguns fire so much faster. I′d also like to have a better firing sound.

I′ve looked through the nexus and haven′t found a mod which does any of this, so if someone knows (hopefully an easy way) to do this, I′d be a very happy scavanger

You can edit those very stats with the geck and save the chenges to an esp. Just look for the minigun entry. Easy way to find it is, click items and type minigun into the text box in the top left and it should be only what appears on the right.

With regard to changing the sound, you would have to create a sound file that you like, create a sound entry in the GECK for that sound and then change the minigun entry to use it. There is a website, freesound.org, that has free-to-use sound effects, you might be able to find something you like there.