I really love these types of videos because it puts my knowledge to the test without judgement, then gives me the opportunity to learn. It feels there are so many similarities between forward facing and rear facing, but it has just enough differences to double check things. My kiddo isn't forward facing yet, but soon, and you've been helping me get more confident.
It depends on the vehicle and the car seat. Britax's top tether anchor has two pieces of webbing instead of one like most seats have, so it always goes around the headrest.
The safest place is wherever you get a tight installation. Middle is preferred for forward-facing, but if you can't get a tight installation in the middle seat, then the side seats are safer.
I just watched a video of a car chase and it showed a car that was hit with a Britax seat installed forward facing using the rearfacing belt path. I see this mistake a lot.
Harness too loose, chest clip too low, car seat reclined, no top tether, latch system too loose (or needs to be seatbelt for weight), back of car seat needs to be extended for head height.
Chest clip too low, too much slack in harness, head position too low, straps below shoulders, no top tether, recline looks like it’s for rear facing, don’t use LATCH for forward facing