Hey there,
thanks for the feedback.
Well, yes, I downloaded the source files from the page you linked here. I have followed the basic tutorial in the wiki of this page.
I started with the recommended build of 1.7.2. When executing gradle I had the problem that he couldn't fetch some data from Maven and completely failed. I tried some things I found in some forums and finally I tried an older release of 1.7.2 and it worked. I followed the tutorial linked in the wiki here and realised that it is for 1.6.2 and that most things will not work in 1.7.2. After that I tried to install an older version of the forge source, but that also failed due to some failed hash checks (but I saw that this seems to be a known bug due to some changes on mojangs side or so)
So, I got back to 1.7.2 and tried the other series from the guy which was about 1.7. But even in that tutorial I saw that things are different and things didn't work, so I assume they have changed...
Regarding the deobfuscated code. I had hoped that I have done something wrong. But the release I used (forge-1.7.2-10.12.0.987), I executed gradle and everything was fine. Everything was build, I got no error messages, I can start MC from Eclipse and so on. I wouldn't know what to do different. Maybe this version doesn't work properly... =)
My Java environment should not be the problem, everything is fresh installed from the ground up, path and java home variables set, so there should be no problem here.
Tomorrow I will start again with a new environment of forge with the recommended 1.7.2 source (or another version you recommend) and post the problems I encounter.
I really hope that it is not that bad as I learned it until now.
Thanks =)