First blood seems like an interesting choice, probably depends on your playstyle and the difficulty you are playing.
I didn't post ED configuration options but I was thinking of pairing First Blood with Shadowdancer for Bring Darkness: "If you have the feat First Blood, the trigger of First Blood now also applies the Darkness debuff, and First Blood now triggers on Harmful Spellcasts." But it's just a rough outline, not a fully fleshed-out build.
I could just do 2rogue for open lock and evasion and 18 wizard,right? Improved evasion would still be nice,no?
Yes, that is always an option. Pros are gaining Evasion which is upgraded to Improved Evasion by the Darkest Luck (Shadowdancer level 26 core); you also have access to Toxin Affinity (+3 Imbue dice for 8 APs). Cons are you don't hit BAB 11 before epic levels so your Greater combat-style feat has to go into an epic slot (which are already pretty crowded); and you lose a feat by dropping the fighter splash.
Basically you're either going to build around having (Improved) Evasion in light armor or robes and raising
your MRR cap as high as you can; or you're going to build around medium/heavy armor (or Adamantine Body) which has no MRR cap.
Also it doesnt look much different if I take the swf line then at 31 take the 2hf specialty VS taking the 2hf line and the swf specialty at 31. One takes 3 feats early on and one takes 4 feats early on.
The main advantage of taking SWF feats in heroics is you need the first SWF feat to take Offhand Versatility and Perfect SWF, whereas you don't need the first THF feat to take Perfect THF. [Finding room for both Perfect ED feats is a separate issue.] Also on the dwarf wizard I posted, I took Knight's Training so I could take advantage of the better critical threat range of battleaxes or longswords (16-20/x4 vs 18-20/x4 for dwarven axes) for higher single-target DPS.