Why two call signs? Back in the '80's, I got a reciprocal call sign while visiting the Cayman Islands, ZF. I've held on to that call over the years so I can operate there any time I visit.
OK on changing signal strength as you drive high on the ridge or down in the valley. Remember, the better antenna is one with the most aluminum up as high as you can get it. Your signal reports are going to be best when you and your LC are on the ridge. That rule holds true with 2 meters and CB, too.
1991 FJ80 converted to an HDT with an A442, Safari intercooler, 3" exhaust, factory Toyota subtank, 3" lift, 285's, Warn 9500xi, rear drawer system, 42qt Engel fridge.