Santali Script
Thanks for your eagerness about Santali and really happy for you!! For that information you have to contact with Santal Norwegian Mission (Norway), Santal Education(Bangladesh),Dumka(India).But unfortunately they don't have any online publication about the santal population and the santali writing script. I may help you to get the information by e-mail (such as I can give you the paper/magazine's screenshot or pdf formates) .
Next point: In our country(Bangladesh) all the santali schools and Christian churches are using the Latin and you may know that the Santali Bible(Christian) is written in Latin Script. But in India the most santals are using the latin. Even our santali grammar is written in Latin script. But nowadays they are going to eastablish the OL Chiki but the OL chiki and Devnagri script useres are a few of numberes(you may find them in Jharkhand,Ranchi). Also You may know that there are some glotal and phonetical problems with OL Chiki, Devnagri,Bangla and we have many debates about those scripts.But the Latin dosen't make any debates.
Software: Yet we don't have any santali script converter software.We have fonts about santali. But recently I made santali unicode typing software and now the santal people are using this software to write santali Santali Typing Software .
Ol Chiki: The unicode Ol Chiki fonts are still under construction Ol Chiki Unicode and some browser don't support the ol chiki(like Internet Explorer,Mozila Firefox).