IO Statistics for Index Seek
Yes, the logical reads include non-leaf level index pages. 

For the index scan in the first query, the first logical page is located by traversing the b-tree to find the first index leaf page, followed by a scan of the entire index in logical order. These stats include the 2 non-leaf pages and all index leaf pages.

For the index seek in the second query, the first logical page satisfying the criteria is located by traversing the b-tree followed by a scan of the leaf pages. These stats include the same 2 non-leaf pages the full scan needed to locate the first page (assuming no rows exist before the key value zero or those are in the first page). The same number of leaf pages are touched because all pages qualify for the seek predicate.

The equality predicate in the third query touches the same number of non-leaf pages of the b-tree hierarchy as the first 2 queries, although maybe different non-root pages, Only a single leaf page is needed to satisfy the predicate for a total of 3 logical IOs.