Do you get both the SP for MRD and the points for the title? or do you need to level MRD first and then get the title? What about a level restriction to people who are new? They need to level a class first in all fairness, due tot hte fact that it would help create more dynamic into getting a title and getting that title to Master. or would there be a level 30-40 requirement to unlock the chance to actually start progressing through said title?
I think the consensus has been that the Title should level up independently of the Weapon Class. This doesn't mean that they can't be leveled up at the same time it just means that sp goes towards leveling up your weapon class, while (job/title points? or some other leveling mechanism) is what levels up your title. You might do something (like maybe combat/leve) that allows you to level up both because it gives you sp/jp at the same time the same way that you level up sp/exp at the same time now, but they are on different leveling curves.

I think because you level them up independently they should be unlocked independently, so you still can start leveling up a weapon class just by equipping that weapon, but you have to initiate a quest to start leveling up a title. Before getting your title you would be like an "adventurer" in FFV just some abilities but no real class definition. You would probably be able to unlock the titles pretty early, like around lvl 20 or something. Alternatively they could have some titles instantly available and leave others to be unlocked.

What if you don't have the weapon specialist that compliments the title you want to play? Do you practically just level up the specialist itself at the same time while you're leveling your title rank?
A weapon class is only going to compliment a title in that the title will have more abilities within that weapon class that favor it. So for example a Black Mage should have far more abilities that favor it in Thaumaturge and Conjurer, then it would have in Weapon Classes like Gladiator and Pugilist.

This doesn't prevent a BLM from grabbing a sword but he wouldn't be able to use the sword abilities as effectively as a PLD because there wouldn't be many/if any abilities in Gladiator that favor it.

Once you started leveling up your title you can always switch between weapons so a r3BLM/r40CON can always switch to his r30THM and be a r3BLM/r30THM.

Also, let's say you start of the game as a THM and quickly get the BLM title, you level it up to r5BLM/r40THM, but now you want to level up CON for some of those abilities instead of doing r5BLM/r1CON, you can switch to your r1WHM and do r1WHM/r1CON so you can level those up together to "kill to birds with one stone" kind of leveling.