Silvering of weapons

 The reason Dracula, of Bram Stoker’s Dracula, hated silver was because it was considered a “pure” metal, as opposed to steel which was an alloy, or gold which was too soft to kill in its purest form. It is also why Dracula had no reflection, because mirrors of the time were backed by silver.

D&D Rules allow silver weapons to harm certain monsters, and players expect to exploit a loophole to create silver weapons by melting down silver coins and coating their regular weapons with it. In strict terms, this wouldn’t harm the Dracula from the book, because it is not the chemical properties of silver/Ag, but the “purity” of the creation made from it. Silvering a mundane weapon does not create a pure weapon. 

Players want to melt silver coins because it is cheaper to do so than to buy a new weapon. The way to make such cost commensurate would be to use a silver standard.

 Allowing players free movement over a map makes keeping STRICT TIME RECORDS practically impossible, especially with dynamic lighting. It’s easiest to do in “theater of the mind” style where the DM is effectively in control of the pace of the party. 

In OD&D, all magical armor is plate armor. Using only the LBBs, this isn’t so much an issue as 2/3 classes can wear magical plate with no restrictions, and the class that can’t, cant wear any armor anyway.
But the thief poses an issue, as that class can wear some limited armor, but not the better armors, and no magical armor.
Meaning that the Thief is practically just as bad as the MU. Worse, actually, as higher level MUs can make up for this deficiency where Thieves never can.