I wish to argue a few points.
1. Spell-casters and the core craft feats. You can disallow the items from being bought/sold, but the players can still make 'em? That is not balanced or fair you are giving and even larger advantage to casters.
2. Multi-classing is not a problem at any level. Why is this such a problem? (Do you allow prestige classes?)
3. Why Miniature Handbook?
4. How about erretas?
Now my opinion about the post: What I see is your trying to limit the players so that they can make weird, overpowered, nonsensical characters. I can do that with only using the PHB, dwarf - druid who shaves, elf - cleric worshiping Moradin and wearing a false beard, gnome - wizard transmuter using alter self, polymorph, polymorph other shape-change and so on. - These are the races and classes that are broken/overpowered compared to the others.
Balance issues start at the beginning, races number wise are not equal (compare the dwarf with the Half-or and Half-elf). Classes like wizard who hold person you and just insta kill you (all spell casters are more powerfull then anyone without spellcasting).
Feats, whats would you rather take Awareness (+2 listen and spot) or the ability to craft magical items?
And lets say Diplomacy? How is that balanced? You can get this to a fairly high score very early, that and spend some points on languages and you can charm anyone at will (1 rounds if you take your time, 1 round if you take a -10).
I recommend taking these steps:
a. If you want to balance things, completely rework how spellcasters and how magic works in 3.X. Without the rework there will be no balance between the classes.
b. Balance out the races, the numbers are all over the place, I recomend removing any core half race to make things fair, OR give the Half- orc and elf some numbers to bring them up to the level of the dwarf, elf, halfling, gnome.
c. Magic items are fine the way they are, very rarely do I see a post trying to fix them. Cause you as the DM can make the item go away via plot.
Final words: If your the DM, its easy to counter the players and keep them in check, "oh so your a Wizard/incatatrix...what ever casting 3 spells in a round? Oh what is that hovering around the corner? Hey looks its the local Beholder and its looking at you....
", "Your diplomacy is how high? The golem does not care much for your smooth talking". "So you took 2 level of monk for the evasion? Roll fortitude." Aaaand so on.
DM trumps BS every day.
1. Spell-casters and the core craft feats. You can disallow the items from being bought/sold, but the players can still make 'em? That is not balanced or fair you are giving and even larger advantage to casters.
2. Multi-classing is not a problem at any level. Why is this such a problem? (Do you allow prestige classes?)
3. Why Miniature Handbook?
4. How about erretas?
Now my opinion about the post: What I see is your trying to limit the players so that they can make weird, overpowered, nonsensical characters. I can do that with only using the PHB, dwarf - druid who shaves, elf - cleric worshiping Moradin and wearing a false beard, gnome - wizard transmuter using alter self, polymorph, polymorph other shape-change and so on. - These are the races and classes that are broken/overpowered compared to the others.
Balance issues start at the beginning, races number wise are not equal (compare the dwarf with the Half-or and Half-elf). Classes like wizard who hold person you and just insta kill you (all spell casters are more powerfull then anyone without spellcasting).
Feats, whats would you rather take Awareness (+2 listen and spot) or the ability to craft magical items?
And lets say Diplomacy? How is that balanced? You can get this to a fairly high score very early, that and spend some points on languages and you can charm anyone at will (1 rounds if you take your time, 1 round if you take a -10).
I recommend taking these steps:
a. If you want to balance things, completely rework how spellcasters and how magic works in 3.X. Without the rework there will be no balance between the classes.
b. Balance out the races, the numbers are all over the place, I recomend removing any core half race to make things fair, OR give the Half- orc and elf some numbers to bring them up to the level of the dwarf, elf, halfling, gnome.
c. Magic items are fine the way they are, very rarely do I see a post trying to fix them. Cause you as the DM can make the item go away via plot.
Final words: If your the DM, its easy to counter the players and keep them in check, "oh so your a Wizard/incatatrix...what ever casting 3 spells in a round? Oh what is that hovering around the corner? Hey looks its the local Beholder and its looking at you....

DM trumps BS every day.