Will I be able to mess with the program after the installer is finished with his work?
Why don't you ask your installer?
Does the editing software come with the remote or do you download it?
See above.
Is programming this level of remote something an "amateur" even wants to try
Depends. If the answer above is yes, you can mess with it all you want. Just don't be surprised to get billed if they have to come out to fix it for you.