The crankshaft is the least of your worries. Honda cranks can hold up to serious amounts of power.

The two main issues are the rods and the lack of a crank girdle. You can have your rods shot peened, or just replace them with stronger aftermarket units. You can add a bolt-on crank girdle from Z10 Engineering, or you can modify a B18C girdle to fit.

Balancing the whole mess would be nice, but not nessicary.

If you don't build it, you risk blowing the engine with 7k+ revs, exactly where LS/VTEC and CRVTEC hybrid engines make the most power.