Economy is vague because it is hard to asses what his impact was. The global economy was doing well and economic growth in GB was slow, but steady. He reversed some Thatcher Trickle-Down stuff from what I remember. Arguably not enough though.

Surveillance is a natural response, but that doesn't make it any better in my opinion. Whenever, there is a prevalent crime the conservatives instrumentalize these events in order to infrige citizen rights. Since Blair did it, that just paved the way for the porn ban and other nonsense. From the outside the UK seems a lot more like a police state compared to other european countries. That said, your police seems to be a lot better than Germany's. Fewer scandals etc.

Overall, I can’t see why you would put his record as “mainly negative” if you exclude the Iraq War.

The Iraq War influenced my rating because it is a big negative for me. And I think a lot of people mainly remember him for that, which is why I assume that he is seen so negative. You are free to judge him differently.