Hi Aurangzeb,
You ask if Sind was a kingdom, the answer is yes and no, but you can read more about it on this link
http://www.encyclopedia.com/html/S/Sind.asp just as the link also gives you information on the religion. Yes they did mint coins in Sind, try a Google search for ‘Coins from Sind’.
Try to search for ‘Wootz’ on this forum, and you will find a lot of interesting mails.
The best way to learn about the weapons is to see as many as possible, hold them in your hand and get the ‘feel’, notice the decoration and remember it. Ask the dealer about the age and history, but beware that some dealers don’t know much, but are very willing at give it a guess, without telling you that he is guessing. Buy books on the history of the land, catalogues and books on the weapons, and join the discussions on forums like this. But the best piece of advice I can give you is, always to be a bit sceptical, as it is not everything written or told which is the truce – good luck with your collection.
Jens