a basic question about mixing plans and backup types

Do different types of backups (full, diff, incremental) reference each other across different plans?

In other words, can I have a plan that does full, another plan that does incremental and so on, or do all the increments and differences need be happening as part of one plan?

Yet in other words :) , if my vault already contains a full back up of a machine or file directory, will a new incremental or differential plan be able to take advantage of it?

To clarify why i'm asking, i wanted to populate the vaults with full manual backups first and then set up a more relaxed schedule that would take care of incrementing the existing backups and allow things like indexing, cataloging, compacting and what not to finish within a reasonable amount of time.
Reading some info on version 10 seems to indicate such approach will not work, the plan names must remain the same for the chain from full to increments to work.
If that is also the case with 11.5, i have another question, what happens when i have a plan that only has an incremental backup in it and i fire it up for the first time? Is it smart enough to make a full backup and only start incrementing on the second run?

thanks!