Wifi near is different in that it won't hold the phone awake between periods of turning on wifi to check for known/nearby wifi connections. When you have an action that just sleeps, it holds a wake lock. Wifi near won't do that.
As far as the time between checks, you can configure that by going to menu->preferences, then select the monitor tab. You'll see a heading for "wifi scan seconds". That is the number of seconds the tasker will wait between polling wifi near while the screen is on. Below that, under "Display off timings", you see a box for all checks. Be careful what you set this to, as it will affect the timings for all the options you saw above (where wifi scan was). The number of seconds you put there will be how long it will wait between polling everything (including wifi near) while the screen is off.
Another thing that kind of throws people off with wifi near is that it will wait two polling periods before turning off wifi. So, if you have the screen-off polling period set to 600 seconds (10 minutes), wifi near will check for nearby SSIDs every 10 minutes. If it doesn't find your connection, it keeps wifi on until it does another poll 10 minutes later. It does this just in case you have a bad connection. You don't want it accidentally turning off wifi. So, yes, it takes longer for wifi to turn off, but it holds a more reliable connection.
Unfortunately, there is no current way of doing this with bluetooth. If I'm not mistaken, "bluetooth near" context functionality is in the works. But having the phone sleep, turn on bluetooth, sleep, repeat, is not a great idea in terms of battery life. A better idea is to define it based on conditions when you know you might need it, like when you plug in your phone (such as in the car) for example. There are many other ways to do it.