heatmap.2 Issues with color Key (values and position)

[ScriptKiddie]

Hi There,

i am a Newbie and am running a Project for my university and i am kind of hitting a dead end here^^.
So any help or tips regarding my problem(s) would be heavily appreciated.

I manged to prepare the data to a point where i can plot a heatmap. Yay Me!

But for the life of me, i cannot figure out how to change the following (1 = highest Priority, 2 & 3 are just nice to have):

1. i would like to change the valus of the x Axis of the color key. The default seems to be Column Z score
   (-2 to 2). But i want to print the actual values of my data (at least some of it. Maybe in steps of 200 or so, i would need to see what fits best).

2. I would like the color key to begin at the upper left corner, so it is in line with the left side of the heatmap.

3. obviously, it would be great if the color key would end on the right side of the heat map. (At the moment it ends with the legend of the y axis)

I checked the usual suspects (StackOverflow, R Documentation etc) , but i am not fluent enough in R to be able to understand enough of it. Plus i think i am not using the correct keywords. So if someone could nudge me in the right direcction...

The heat map code is as follows:

#used librarys
library(ggplot2)
library(dplyr)
library(RColorBrewer)
library("gplots")
library(lattice)

# followed by lots and lots of data manipulation :-)

# create heatmap
heatmap.2(data_matrix
          , dendrogram = "none"
          , Rowv = FALSE
          , Colv = FALSE
          , scale = "column"
          , trace = "none"
          , margins = c(10,12)
          , cexRow = 1
          , cexCol = 1
          , col = colors
          , density.info = "none"
          , keysize = 0.75
          , lmat = rbind(c(3,4), c(2,1)))

Thanks a lot!

Best
S.