What kind of research I can do with my data set? I have a data containing 200K ads (sale and rent property in the United Arab Emirates, or UAE). Here is a sample:

190459 obs. of  29 variables:
 $ id                  : chr  "tnydu.biz/DafdVO" "tnydu.biz/DafloP" "tnydu.biz/Dafmvy" "tnydu.biz/Dafuy5" ...
 $ AdType              : chr  "sale" "sale" "sale" "sale" ...
 $ AgencyFees          : num  NA NA NA NA NA NA NA NA NA NA ...
 $ Amenities           : chr  "CentralA/C&amp;Heating,SharedPool,SharedGym,Security,BuiltinWardrobes,ViewofWater,ViewofLandmark" "Study,CentralA/C&amp;Heating,Balcony,Security,MaidService,CoveredParking,BuiltinWardrobes,Walk-inCloset,BuiltinKitchenAppliances,Vi"| __truncated__ "CentralA/C&amp;Heating,SharedSpa,Security,ConciergeService,MaidService,CoveredParking,BuiltinWardrobes,Walk-inCloset,BuiltinKitchen"| __truncated__ "CentralA/C&amp;Heating,Balcony,Security,CoveredParking,BuiltinWardrobes,BuiltinKitchenAppliances,ViewofLandmark" ...
 $ AnnualCommunityFee  : chr  "9000" NA NA NA ...
 $ AreaDescription     : chr  "\r\n            \r\n                \r\n                    1.9 km from Najmat Reem Marina\r\n                \r\n            \"| __truncated__ "\r\n            \r\n                \r\n                    0.3 km from The Dubai Mall\r\n                \r\n            \r\n "| __truncated__ "\r\n            \r\n                \r\n            \r\n        " "\r\n            \r\n                \r\n                    0.7 km from The Dubai Mall\r\n                \r\n            \r\n "| __truncated__ ...
 $ Bathrooms           : num  1 NA NA NA 5 3 NA NA 3 3 ...
 $ Bedrooms            : num  0 3 0 1 3 2 2 2 3 3 ...
 $ Building            : chr  "HydraAvenueTowers" "BurjVista1" "TheAddressDubaiMall" "TheAddressDowntown" ...
 $ City                : chr  "AbuDhabi" "Dubai" "Dubai" "Dubai" ...
 $ PublishDate         : POSIXct, format: "2015-10-30" "2015-11-11" "2015-11-13" "2015-11-09" ...
 $ DealerCode          : chr  "599942" "604296" "604296" "604296" ...
 $ DealerName          : chr  "STARWOOD PROPERTIES BROKER" "BLUE PALACE REAL ESTATE BROKERS" "BLUE PALACE REAL ESTATE BROKERS" "BLUE PALACE REAL ESTATE BROKERS" ...
 $ Developer           : chr  "HydraProperties" "EMAAR" "EMAAR" NA ...
 $ Furnished           : chr  NA NA NA NA ...
 $ ListedBy            : chr  "Agent" "Agent" "Agent" "Agent" ...
 $ Location            : chr  "City of Lights, Tamouh Marina Square" "Downtown Dubai, Dubai" "Downtown, Cairo" "Downtown Dubai, Dubai" ...
 $ LocationGPSLatitude : num  24.5 25.2 30 25.2 25.1 ...
 $ LocationGPSLongitude: num  54.4 55.3 31.3 55.3 55.1 ...
 $ Price               : num  900000 3822888 2150000 3200000 5500000 ...
 $ PriceSqFt           : num  1129 2185 3909 3422 2431 ...
 $ PropertyReference   : chr  NA "BP9801" "DT-K20" " BP8958" ...
 $ PropertyType        : chr  "apartment" "apartment" "apartment" "apartment" ...
 $ ReadyBy             : POSIXct, format: "2015-04-30" NA NA NA ...
 $ RentIsPaid          : chr  NA NA NA NA ...
 $ ShortLink           : chr  "tnydu.biz/DafdVO" "tnydu.biz/DafloP" "tnydu.biz/Dafmvy" "tnydu.biz/Dafuy5" ...
 $ Size                : num  797 1749 550 935 2262 ...
 $ TotalClosingFee     : chr  NA NA NA NA ...
 $ VirtualView         : chr  NA NA NA NA ...


I'm looking for help figuring out what kind of questions I can answer using these data.
For example,
1. What the mean price per year for a 1-bedroom apartment to rent in different areas of Dubai?
2. How are supplies for apartments and villas distributed on the city map?
3. Does the number of bathrooms influence on sale/rent price?
4. Where is the best place for investing to get more profit from apartment cost and rent revenue? 

I have already done some of this (plotted the map with mean price for studio in Dubai in thousands AED/year, 1USD = 3.66AED):



From your experience, what other questions can I ask? What I have to be aware in this data set? I can share my data set if anyone want to examine it (it is a 12mb zip).
There are several things that can be done, however as @Dawny33 mentioned, start with the problem you want solved. 

As an example, If I was trying to solve: Which factors, influence the prices and how?

A simple analysis could be to run a linear regression model (lm) with PriceSqFt as a dependent variable and others as regressors. You can then select top 10 or 15 or how so ever many you like and look at their relationship.

This may help you answer some simple questions like: 

How do prices vary by dealers, by property type, by location, by size?
Does move in ready date make a difference to rent / prices?
Do specific kind of properties have later than usual ready dates?
Is there a negative or positive correlation between size and pricesqft?
Are certain dealers over or under priced compared to other identical
properties and location?  


You can also create a plots using pairs or other functions to look at pairwise relationship for initial analysis and building on top of what you see.

If you really want to take it a to the next level, you can create a prediction model to predict the price based on select parameters.