Transparent Data Encryption and impact on backups

I have a customer who is looking at implementing TDE - At the tablespace level.

It looks to me as if there are no restrictions on data types that can be encrypted if implemented at TS level.

I am assuming that the basic method (ignoring wallet creation etc) is to :-

1) create tablespace with encryption enabled

2) 'Move' objects to new tablespace either by data pump , CTAS, Alter table ...move or using the dbms_redefinition package

Would that be correct ?

One other question that has come up is whether there is any impact on the size of RMAN backups once encryption has been enabled.  I am assuming that their should not be but if someone could confirm either way I would be grateful