So far I have two flavors:
rogue 2/fighter 2/wiz 3/ spellsword 1/ bladesigner 1
STR 14, Dex 16 (18), Con 14, Int 17, Wis 8, Cha 10. HP 55 BAB +6. AC: 24/25 dodging, Longsword +9/+4 (d8+3). F/R/W: 8,9,6.
combat casting, combat expertise, dodge, weapon focus (long sword), scribe scroll, sneak attack +d6, evasion, ignore 10% spellfailure, dodge, mobility, bladesong style. Casts spells as wizard 5.
gauntlets of dexterity+2, amulet of natural armor+2, ring of deflection+1, mithril shirt+2, keen longsword+1, slippers of spiderclimbing, 3800 gp left over
This version had a good skills (nothing wasted cross-class), good AC, so-so combat abilities, but gets sneak attack and evasion, poor damage output, and moderate spellcasting.
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Swashbuckler 3/Fighter2/Wiz1/Bladesinger 3
STR 10, Dex 16 (18), Con 14, Int 18, Wis 8, Cha 12. HP 66. BAB +8. AC: 21/22 dodging, Rapier +13/+8 (d6+5). F/R/W: 9,9,4.
Combat casting, Dodge, Combat expertise, Weapon finesse, Weapon focus (rapier), Mobility, Elusive Target, Scribe Scroll, Grace+1, Insightful Strike. Lesser Spellsong. Casts spells as a wizard 3.
gauntlets of dexterity+2, amulet of natural armor+2, ring of deflection+2, keen rapier+1, slippers of spiderclimbing, 800 gp left over
This version has batter combat capabilities, HP, poorer AC, and weaker spellcasting.
Also, the rules for the bladesong style say that you need to keep your hand free. Technically, a buckler does not require the use of your off-hand. Can you use a buckler and still benefit from the bladesong style?