I know that I can just hammer through the Kingdom areas, but I really do like the environment. I'd like the time and freedom to actually explore it, but the game doesn't really offer that option. You've gotta be rushing or crawling through it.

You mean during the actual assassinations?

As for the roof guards, I've started encountering more of them. The escape after killing the Merchant King in Damascus was a bit trickier than the previous three.

I still have yet to find a genuine use for the vigilantes. I can see your strategy coming in handy, but as of currently, I haven't found a situation that really warrants the need for it.