If I can create a second FTP account for editing the site, ...
FTP is for file transfers only (uploads and downloads), it is not an application for managing web sites like the cPanel.
If you really want to manage a wiki using wikkii's advanced hosting service, there is really no shortcut, you will simply have to learn how to administer all these MW extensions, php coding etc. There are forums that you can visit for assistance, some have been listed in the hub.wikkii.com
If you find these are all too much for you to handle by yourself, you may wish to look for alternative wiki hosting sites. Use your search engine to perform a query for 'wiki farms' and you should be able to find some. The more well-known ones currently are wikia, shoutwiki etc. Please note that my statement above should not be seen as an endorsement of any of these sites.
Exercise your own judgment when selecting which service to go for.