Hi Bob
I have kept anemones and clownfish for six years so I do have some experience that might help answer your questions.
If you want to move the LTA using a credit card you can do so, just be careful not to tear the base in any way-slow and gentle is the secret here. If you don't have the patients then you could always use a small powerhead to gently blow the base until it moves onto something placed behind it's foot such as a small piece of plexi glass or a bottom piece of icecream tub. I have used these materials in the past as it makes removing the foot much easier when introducing it into the new tank.
As for any problems with the two larger Perc's taking up in there new host.
I would see no problems with that what so ever. The only action that I think will probably happen is that the larger female will most likely keep the male at bay and not allow him into her new host. This is perfectly normal however and happens in nature, so it would be no reason for concern. The male would probably keep to the conch shell or it might even take up territory underneath the new host. When the LTA get's big enough, the female may even decide to let the male into the anemone with her.
From my expierence anyways
, cheers Rich