1] What was the origination of Scotland Yard?
The name of the police headquarters came from the name of the area of Great Scotland Yard that 4 Whitehall Place [original police HQ’s address] backed onto. As can be seen from on the sketch map [plate 92] accessed from the british-history link at 2, there were two parts of the original Scotland Yard and there was also a Scotland Dock. Although Wikipedia states “the origins of the name Great Scotland Yard are unknown”, it would appear that the Great Scotland Yard was formed from the two smaller sections during later rebuilding works, it’s those yards and the dock that the origins of the name are unknown.
The London Metropolitan Archives will have more maps and perhaps other documents of interest to you, although you may need to employ a researcher to help you. See http://www.cityoflondon.gov.uk/Corporation/LGNL_Services/Lei...
2] who of the royal employees would have been granted lodgings there as a part of his employment perks?
From looking at the list of names and also the names on individual premises, it’s possible that not all the earliest tenants were Royal employees, but they would have been tenants in property that was on Royal land, the properties’ land then subject of a sub-lease from the builder/owner of the buildings who held the main lease. You’ll find a list of some of people or their positions within the Royal Household, employment or Civil positions listed on the map.
If you believe you had a relative who lived in a royal owned house or was a member of the Royal Household, there may be a record in the Royal Archives, see http://www.royal.gov.uk/The%20Royal%20Collection%20and%20oth...
> Frequently Asked Questions
You’ll find a history of Whitehall Place and Scotland Yard starting at http://www.british-history.ac.uk/report.aspx?compid=68131
there’s some information on the earliest tenants and much more. Starting at the 68331 page with a general description and an excellent sketch of the whole area c1670 [plate 92], the next page describes Nos 1 & 2 Whitehall Place, followed by a page associated with Nos 3 to 8 and finally with a page describing the area of “Scotland Yard” itself; there are a number of smaller sketch maps too. Note the when looking at the foot notes [click fn. #] references to P.R.O. [Public Records Office] are now TNA [The National Archives].
3] Are any of these old buildings still a part of the Scotland Yard complex?
No, most of the buildings that surrounded the areas of Scotland Yards shown in the c1670 map were demolished before the newer Whitehall Place was built, all described in the text link at 1. The original Police HQ was moved from Whitehall Place to the Victoria Embankment in 1890 and moved again in 1960 but the 1890 buildings are still used by the police. For more history see http://en.wikipedia.org/wiki/Scotland_Yard
Hope that's of help, Jeff