Range just changes spindle direction, period. Engaging backgear changes spindle direction, so you need to reverse spindle (motor) direction.
Grease in hole "A". Squeeze it in and estimate the volume.
I'm not familiar with that grease/oil? fitting in the front... never seen one there before. Maybe someone else can help??? I'd have to see where the grease/oil would end up going when the head was taken apart... Remember, some zerts take oil not grease.
Looks like there's is something up in the kick out linkage. Removing the ball: Never had this issue, but the ball needs to come out. Can you make a small scraper out of an old small file and work the hole around the perimeter of the ball to open the hole up? Must be the hole is burred over holding the ball in. Or, maybe if you have a small rotary file bit on a Dremel (or whatever) you can work the hole opening??? You might ruin the ball, but they are easy to replace.
Speed change. Open it up; you should not have to remove the pin. Just re-wrap the chain in the correct rotation (direction) by turning the crank the other way when you have it removed. IIRC, this is all you have to do. I had the same issue when I assembled my first one.
Good luck,
Ted