I think what you need to understand is that transcription factor genes like SP1 produce transcription factor proteins that can then bind to the transcription factor binding sites of other genes which are often in the promotor region of those other genes. (Some transcription factors may be self regulatory and thus have a binding site in their own promotor region).

Answering your questions from that perspective:

1. Yes. If you know the location of any gene you have a clear indication of where the promotor region is, just in front of it. (That is matter of definition actually, sometimes promotors are considered part of the gene). But you might really want to ask "do I now also know the regions where the transcription factor binds?". No for that you would need the binding motif and then scan the genome where that occurs. Nowadays you could use experimental data to see where the transcription factor really binds in different tissues, e.g. from ENCODE.
2. No, it does not tell you about histone modifications. But if you know from epigenetics analysis where these occur you can see whether that is indeed in this region.
3. The difference between the 2 genes probably also is a matter of what exact region the two resources consider to belong to a gene (which should be in the provenance descriptions for the gene annotations). They are just 100 bp apart in this case.

I did some work a while ago (in bacteria) using LexA, a self regulating TF, to extract binding motifs using a comparative genomics approach. Basically if one can reasonably assume that the TF self regulates, there will be a binding site for that TF upstream of its gene.

So you gather a number of related species and identify the TF orthologs and then use MEME to mine promoters for a binding motif.

You could presumably do this work if there were enough copies in of your TF's gene either in a single species, or related species (for humans you could use primates).

However, that is only if you don't know what genes your TF is acting on, if you have a list of genes known to be regulated by your TF, you can hit the promoters of those genes with MEME or some other motif discovery tool.