There's a misconception over the phrase 'ToT' - it doesn't imply a blanket transfer of the technology involved in manufacturing every single material (and components fabricated from said materials) in the system. ToT can be to varying degrees. Some of the most critical and secretive technology is in fact in materials engineering - the materials used to fabricate the jet engine blades for example, and I doubt Pakistan is trying to obtain that particular information for in house fabrication at this point in time.
From what I understand, these initial discussions are for a repair and overhaul facility. The next step would be local assembly of engines from imported components after which you might see a gradual increase in locally produced components.
Since China, at this point, is not inducting the JF-17 (Their single engine fighter needs are being met by the J-10), I don't see how the Chinese played a role.
Putin is, if nothing else, a very proud and nationalistic Russian leader - the argument that he was arm-twisted by the Chinese into providing engines for a Pakistan specific fighter jet isn't a strong one. The Chinese may have engaged with the Russians on Pakistan's behalf, but even they would not burn their influence with the Russians over an engine.
To understand why the Russians agreed to supply the engines, just take a look at the current state if Russia-Pakistan relations - there is increasing engagement on military and economic issues. These developments did not occur overnight - the engagement between military and government officials has been occurring for years now. The agreement to provide engines for the JF-17 was one of the first tangible steps taken as part of that engagement process.