Washington Insider, But Wall St. Pariah
Multibillionaire Charles R Schwab, founder of discount stock brokerage, has influence with Bush administration and his proposals may help government rekindle investors' enthusiasm for stock market; his competitors on Wall Street disdain Schwab, accuse him of disingenuity and foresee continued shrinkage and waning of earnings for his firm; photos; graph of Schwab & Co financial statistics (M)