Germany Government

1/4. Two main political parties are CDU (Christlich-Demokratische Union Deutschlands or Christian Democratic Union of Germany) is Germany's main conservative party and SPD (Sozialdemokratische Partei Deutschlands or Social Democratic Party of Germany) grew out of the 19th-century labour movement and was originally a Marxist party. 
http://www.expatica.com/de/about/The-main-political-parties-in-Germany_107953.html
2. Federal parliamentary republic,federal legislative power lying with the Bundestag (German Parliament) and the Bundesrat  (a federal council representing Germany's 16 länder or federal states).
The Head of State, the Bundespräsident, elected every 5 years by the Bundestag and state delegates, has a largely ceremonial role. Yes The Bundeskanzler (Chancellor) is the Head of Government, elected by and responsible to the Bundestag usually for a four-year term, is almost always the leader of the largest party.  Federal republic.
http://www.expatica.com/de/about/The-main-political-parties-in-Germany_107953.html
3.Around 11 parties.
5. All these parties,11, are officially recognized.
6.The main two premises the parties are based off are economic and social issues.
7.The federal chancellor is the only member of the federal government to be elected. The constitution empowers him to personally choose his ministers, who head the most important political authorities. Moreover it is the Chancellor who determines the number of ministries and their responsibilities. It is he who lays down the guidelines of government policy. These outline the Chancellor’s right to stipulate binding government activities. This authority gives the federal chancellor  a whole array of instruments of leadership that easily stands up to a comparison with the power of the President in a presidential democracy.
http://www.tatsachen-ueber-deutschland.de/en/political-system/main-content-04/the-federal-chancellor-and-the-government.html