did you try plugging it into another comp....pc or the like?
It's a tough call...If it's somebody's home then you are "out of bounds"...however, if your main subject is a beautiful oak out in the distance and the house happens to end up in the frame....well....The best way is to ask permission because you are really violating someones personal space...not everybody is cool with that...there's several articles on the subject...ps.
I believe the 70d is a crop frame which would mean you're actually shooting at around 25 m. I used the the canon 10-22 for a long time with great results..The 10-22 would be shootong at 16 m on a crop sensor
Both Canon 5d 3 and 4 are great, however, I wouldn't dismiss the Canon 7D mark 2 !!