Creating an alternate Battletech Universe

Of course I have no clue how to go about it.  I've never been completely happy with the canon and over the last week or so, I've been thinking about finally going ahead and start fleshing out My Battletech Universe (MBTU).  I've thought about it and have made a few assumptions, but every time I sit down to write it down I get distracted making vehicles of my own design or fiddling around with Gimp to make my own paper miniatures for play.

So I'm going to jot down a few assumptions or concepts I want in MBTU so I have a place to review them and to see if anyone wants to give me some feedback on these or other general pointers on moving forward.

• MBTU will have many more factions;  think Europe during the mid-11th century
• The technology is limited to Inner Sphere tech that is still in production in 3001; no left over tech from the Star League era
• No instant communications (HPG) and therefore no ComStar (at least in the canon meaning)
• There will be mercenary free companies, but no MRBC
• Mechs and vehicles are expensive, so there won't be individuals that bring their own to their unit when the sign up
• Most organized units should have a limited number of mech/vehicle types for logistic purposes

I'm thinking of using some of the Traveller rules to help flesh out a few polities to get an idea of their economic resources and build from the bottom up.  This way I can setup a few scenarios to play without creating the entire BTU, and slowly fill in the details as I go.