1. I used Paragon Partition Manager 11 on Windows XP running in VirtualBox virtual machine. There 3 things to know - do not touch partitions at the beginning (recovery, uboot, e,t,c), you need enough free space on your READER partition and you have to work one partition at a time starting from the biggest one and making sure operation is committed before doing next one (tool allows you to commit multiple operations in sequence or batch mode - do not use it!)
All necessary partitions (but /system) could be done "in-place" with all data intact in about 5 minutes. If you want to change /system (which is not necessary) - it is ext4 - and tool (despite what is declared) cannot handle it properly, so you have to use tar to save data, delete and create partition and restore.
2. Yes - you have to be in recovery mode with my backup and recovery SD card
3. Yes - you reduce READER partition and than move and enlarge next one e.t. c. There is one additional step - enlarging "extended" partition to which (if my memory does not fail me) data and system are children. Unfortunately I did it some time ago and do not remember all the details - but it was not difficult.
4. I did backup first and had to recover once in the middle of procedure because I was trying to do something tool was not capable of doing. So do backup - it takes several minutes and is easy.