Hi,
1. It depends which items needs market valuation, for eg in case of gratuity actuary is the best person, for investment properties there are various independent valuers available, in case of investment held to maturity market value of the investment based on the stock market rated and financial statements for listed and unlisted securities respectively. In other words, it look more easy to write however too difficult to practice in a place like India where things are too much extend unorganised
2. Frequency is usually wenever one prepares financial statement.
3.A very vague statement "other requirements"
4. Too difficult for valuers to fulfill the requirements of IFRS with regards to fair value. Good opportunity for exisitng valuers but not for a newbie.