Know what a city holds for you before you go

Yes, that's the point. Your lines exist across the whole planet from the moment you were born, whether or not you've ever gone there. Checking a city before you book anything is the most useful way to use this.

Strength is how close your city sits to that planetary line, converted to a 0 to 100 number. Above 70 the line is a defining feature of the place. Between 30 and 70 it colours things. Below 30 it's background noise you'd probably never name.

A paran is a horizontal band of latitude where two planets touch an angle at the same instant. Unlike ordinary lines, which run roughly north-to-south, a paran runs east-to-west, so it can affect a whole row of cities at once and explains sharp differences between places at the same longitude.

It happens, and it isn't a bug. If no planetary line falls within about 1,100 km, the sky is simply quiet there. Quiet places can be excellent. Nothing is pushing you, so what you build is entirely your own. You'll still get the eight life-area scores.

For this tool, yes. It matters more than in most astrology. The Midheaven and Ascendant lines shift roughly 15 degrees of longitude for every hour of error, which can move a line across an entire country. If you're unsure of your time, treat the reading as directional.

No. Intense usually means fast and demanding rather than harmful. Saturn lines build careers, Pluto lines rebuild people. What matters is whether you want that particular workload right now. The reading tells you what the place asks of you, not what to do.