Gemma - if you are the joint owners then when you transfer plot A to Jake you would use form TP1 to do that and that would split the title. You don;t split first and then transfer it.
So you would be lodging a single form AP1 against the single title
1. Panel 4 of form AP1 would list the order of the transactions for example Transfer of part > Severance or Form A restriction > Change of address
Much will then depend on how you
sever your joint tenancy and how you want to
change your addresses but you can do it all under the one application and provide evidence of identity for both of you as appropriate
2. Transfer of part Plot A
3. The only fee would be for the Transfer of part - and if the transfer is a gift then it's Scale 2 on the current market value of the transferred land. The discretion element is only if it was a split and both parts staying int he same ownership, which it isn't.
4. See earlier advice
5. Whilst you can use the specific form as linked you can do it all as part of your one application in form AP1 provided you make it clear what your new addresses are and provide the confirmation re identities