1 & 2 - Feature updates include all the cumulative updates before them, so installing them will remove need for the CU.
3 see above
4 CU only install updates you need. They used to include everything, even stuff you didn't need. Now they only install updates for things you use.
5 Originally the Feature/Version updates were meant to be every 6 months but problems happened and now its roughly every 6 months. Since this was released in May have to assume next one is November.
CU come out on the 2nd Tuesday of the month, or do normally