1) in the webassist/themes folder, delete the other folders for themes you dont wish to use, except for the default theme folder, that one needs to be kept.
2) Yes, the install folder should be deleted once the install is complete.
when you upload to the live server, you wont be running the install routine again, so should not include the install folder in the upload.
When you transfer to the live server, you'll need to use PHPMyAdmin to export the local database and then import it to the live MySQL Server.
then update the connection file top connect to the remote database and upload all files except the install folder.