strange noone answsered yet....
Question #1: if the instance is stopped, it is not considered as consuming a license
Question #2: not clear. If you mean if you keep the product on lpar A, you do not need to install neither SDK or 4GL on this machine A again, because they are already present and functional. This will be even easier because you will need no changes for the application users. the only difference is that you must change the hostname in the sqlhost file (going to lparB instead of lparA)
You also do NOTneed to install 4GL & CSDK on lpar B