All you need to install your e-Sword X module at no additional cost is to enter your Email address and "Product Key" you received when you purchased the module for use with e-Sword. If you do not have that information, just click on the "Recover Product Key" button on the dialog that prompts for this information.
When you attempt to download a "locked" module it will display a dialog prompting for your "Product Key". On that dialog is a "Purchase From ..." button that you can click to be redirected to the publisher's web site for pricing/purchasing if you wish to do so.
No. E-Sword X is an "offline" app. An Internet connection is only needed for downloading the app itself, and any additional modules you wish to install.
No. Only Mac models running at least OS X 10.11 El Capitan which is available for all generations of Mac built from 2008/2009.
Check out the online Help file here:
Kevin Purcell has created a great online demo you can view here:
There is a lot to it, but hopefully we can make it easy for you. The following steps should assist you in this endeavor:
STEP #1 — e-Sword. You need to have a PC with e-Sword 11.0 installed on it. You can download that from here: https://www.e-sword.net/downloads.html
STEP #2 — Content. There are thousands of user-made modules already available for e-Sword which can easily be converted for e-Sword X. Join the e-Sword User Group where you can find what you are looking for, or if it doesn't already exist there are also tools by which you can create them! The e-Sword User Group is here: http://www.biblesupport.com/
STEP #3 — Convert. After you have downloaded the e-Sword module(s) you wish to convert for use in e-Sword X you will need to run them through the e-Sword PC Module Conversion Utility. You can download that from here: https://www.e-sword.net/extras.html
STEP #4 — Transfer. The final step is to move the new module(s) onto your Mac. Select "Import" under the e-Sword X "File" menu item to do so.
STEP #5 — Restart. To load the new module(s) you will need to restart e-Sword X if it is already running.