I've checked out the website(could someone post a link, I'd make the attempt but it could be messy.)
http://www.planewalkergames.com ? (Unless the URL has a lot of wacky symbols, the forum software will automatically format anything with the http prefix to a clickable link.)
Why the name, 'The Broken Hourglass'?
It speaks to the game's plot, which we'll gradually release more details about as the game gets closer to release.
Will there be scripts or other automatic ways to set individual npc A.I.?
Some of the details of party AI are still under development, so we'll have more details on this at a later date.
How will the inventory or equipment system work? Will there be encumbrance issues or attribute/class restrictions for armour/weapons etc.?
Yes, there is a concept of encumbrance. Your stats determine how much you can carry before you start suffering speed and stat penalties. There is no hard numerical limit on the number of items one can carry. There is also a special pool of "party inventory" which does not encumber anyone in the party, but also isn't directly available for use unless you pull it out and give it to a character (which would cause you to drop your guard in combat, etc.)
There are no "class restrictions" as there is no pure class system. We will offer class "templates" for leveling, but investing in a spellcaster path doesn't preclude you from using pointy weapons or armor or something like that. Of course, the spellcaster putting time and energy (and points) into mana and fire magic may not be terribly good with a greatsword.
Will there be relationship development/immersion with the npc companions - romance/friendship, quests etc.?
Look who you're asking, here.

Yes, the NPCs will be interactive with the PC and with each other, and yes, there will be romance and relationships.
Finally, will it be accessible for purchase on physical media for overseas buyers?
At the very least, we will offer direct worldwide shipping, yes. When we have a finished product we will take another stab at getting regional/retail distribution, but I'm not holding my breath.