The people of Turkey are generally friendly and welcome visitors.  This is partly because the country recognizes that tourism is a key income earner.  The government has institutionalized this by creating a tourism police force to protect tourists.  Visitors to Istanbul will see their obvious presence in tourist areas such as Sultanahmet.  People who harass visitors will likely be subject to just punishment.

However, like most countries, there are bad apples especially in the retail trade and restaurants business, when touts may act rather aggressively.  This can happen in big cities and even in small towns like Kusadasi where a shop selling Turkish Tea tried to charge a highly inflated price and refused to be rebuffed.  This was a bad case, but could have been reported to the tourism police for action.

While it is said that over 80% of the people in Turkey claim themselves to be ethnic Turks, there is some debate about this based on the findings of various studies about the genetic origins of present-day Turks.
Ethnic Turks migrated into Turkey mainly after the invasion of the Seljuk Turks from Persia and their defeat of the Byzantines in 1071.  Therefore, the Turkish language obviously originated from this source.  However, the genetic make-up of the population is blurred by the events of history as the Turks came later than most other invaders and migrants.  Turkey had its indigenous inhabitants such as Hittites from ancient times, and people of many races also moved into the region from time immemorial and stayed there in long stretches: Persians, Greeks, Celts, Romans, Arabs, Mongols, Kurds, Armenians and others.  

It is interesting that the Ottomans saw themselves less as Turks than the embodiment of a much larger enterprise, treating all races rather equally and in fact had a preference for Caucasian women in the harems.  Even some foreigners saw the Ottoman Empire as European, like Peter the Great's assertion of the Ottomans being the sick man of Europe.  It has been claimed by some that many Turkish people have some dose of non-Turkish blood; of course this is a matter for geneticists to work on.