Interesting TL. I've read the first few posts, and nothing about the reforms has really jumped out at me other than decriminalizing homosexuality (which would still have been illegal in Europe at the time). Though to be extremely nitpicky, "Mirza restoration" seems an odd name-the Meji Restoration was called that because the reformist Emperor Meji deposed the Takaguwa Shogans-who had effectively ruled Japan for the last several centuries-and "restored" the political power of the monarchy. I don't see a similar event happening in Iran.
And the Afghan campaign needs some work. A few pointers:
1. The Durrani dynasty had been deposed by Dost Muhammad Khan, who founded the Barakzai dynasty. Herat at the time was an independent state ruled by a Durrani remnant, and wasn't reincorporated into Afghanistan until after the whole adventure with the British.
2. The fact that Pashto and Persian are in the same Indo-European subfamily would have meant about diddly. From the point of view of Persians at the time, Pastuns and Turks are equally foreign people speaking unintelligible languages. Persian at the time was considered the dominant language of culture in central asia, and educated Turks/Pashtuns would be expected to know Persian and be familiar with Persian literary culture and court ettiquette. The real cleavage would be religion-specifically Sunni/Shia-and this works against a prolonged rule of the (Sunni) population of Afghanistan by (Shia) Iran. The Shia clerics in Iran would demand the application of Shia jurisprudence throughout all the Shah's domains, even the Sunni parts, and the Sunnis would resist this. A Persian-ruled Afghanistan could well become a bleeding wound, prone to significant revolts every few years and requiring large garrisons of troops to keep it in order-which would, of course, weaken Iran against external enemies like Russia. (Note that Sunni Herat would present similar problems, but its a much smaller area and much closer to the Qajar power base than, say, Khandahar or Kabul)
If Iran does take over Afghanistan and hold it, then this might provide an incentive for the Shahs to move away from Shiism as a unifying ideology and towards European-style romantic nationalism, emphazing the cultural similarities between Persian-speakers, and even between, say Persians and Turks or Pashtuns. However, I just don't see Iran being exposed to European thought enough to really do this until the later half of the 19th century, and the clerical elite (Sunni and Shia) would be very upset.