1) Not necessary but makes it easier. Alternatives is to mark the line in intervals with marker, or use meter line (changes colors every 25 ft), or buy a clip-on line counter. The okumas are not very expensive but work well.

2) just fine in size

3) yes, borrow a handheld gps to figure speed or some smart phones have apps that will show gps speed.

4)3 or 4. Either side and out the back.

5) Wise rod tender (twin-pack) works for me, but lots of good options out there, just depends how you want to mount them and the type of spread you want between the rods.