A) The number of free float of share will affect the liquidity of the stock. For example if the free float of share is less the company will trade at low liquidity while the beta of the stock just measure the volatility of the stock price itself. Generally it does not affect our decision in investment. Personally, i do not focus on free float and beta.
B) In most case we do it annually. For quarterly, you just need to ensure that the company balance sheet remain fundamentally sound. Personally, for the medium and large companies i only track them once a year while the smaller companies i track them quarterly.
C) In most cases we track using net profit. Only for companies with high depreciation like breadtalk, you can track by EBITDA or Cash flow