I reviewed some of the terms and conditions. These could be good bonuses BUT you will eventually need to make a deposit if you expect to withdraw the profit made from trading using the bonus money.
In the case of the $3500 bonus with Instaforex, you need to do this within a specific time frame.
"The Client agrees that the account credited with InstaForex StartUp Bonus will be converted into a demo account in case no deposit is made within 7 days since the Bonus is received."