Help me migrate from permissions 3.x to ...any new permissions plugin

OK this is how it will work.
I will start off by listing the current setup for my server and list all plugins active on the server.

Then i will ask simple questions regarding concerns i have about the migration.

3rd i will ask how to set up specifics that wont limit the expansion of the server in the future. I will try to determine what steps need to come first when initiating the migration.

myminecraftvps...
Currently using permissions 3
Single world with nether "subworld"-- plan to expand in the very near future.
users currently change groups and thus permissions when entering different worlds.
we use timerank to ensure automation of regular user group placement.

Plugins:
AntiXray--soon to be replaced
BigBrother--soon to be replaced
Deathcounter
Essentials
EssentialsChat
EssentialsGeoIP
EssentialsProtect
EssentialsSpawn
Factions --critical to this world
HomeX --cant seem to find the post on this plugin anywhere, is it dead?
LWC
Lockette -- yea i know they do the same thing but currently lwc is a donation perk
MineBackup
MinecraftRKitPlugin
MultiInv_2.3.0
Multiverse-Core
Multiverse-NetherPortals
Multiverse-Portals
NSCommand
NoCheat
Permissions (3.x)
PvPReward
SpamHammer
Spout
Statistician
TimeRank -also critical to this world
VirtualShop
WorldEdit
WorldGuard
deathcounter-0.3.2
iConomy
mxAntiPVPCheat

ok on to my question
1. which permissions plugin is best for my setup, or do i need one at all?
2. whats going to break when i migrate?
3. what can't be avoided?
4. should i use Superperms to create custom nodes for users? or just add nodes to each group?
5. do i need multiple groups for multiple worlds and have a mechanism for switching groups when entering a new world
6. or define permissions per world in the group?
7. do all the permissions plugins have default groups?
a. how are users added to default groups?
b. can i have default groups for individual worlds or subworlds?
8. do i lose some of the functionality/ease of use of multiverse if i set things up a certain way?
9. is there some way to disable plugins entirely on specific worlds with SuperPerms?

many more questions...everything just seems to work right now but with the migration...so many things to worry about as permissions are the foundation of every server using them.

 

bPermissions has an import function. You can move from Permissions 3 to bPermissions in one step. Use bPermissions 1.2.2 or later.

Just delete Permissions.jar
Install bPermissions.jar

Run the command /p import p3

 

Use Pex , its deadly simple , just copy-paste your config

 

just copy paste even with 3.x? everything i see in the thread says 2.7