You're welcome - and thank you for persevering
Now that you have got your head round the TaskChain for Moodle 2.x files, I suggest you investigate the Moodle 2.x repositories. They allow you to store your files somewhere outside Moodle and then link to them - assuming that you are using Moodle 2.3 or later. This makes it possible to share the files between TaskChain activities in much the same way as activities used to share files using "Course files" in Moodle 1.x.
The particular repository type that I use most is the "File system" repository.
This kind of repository is a folder on your server's hard disk. Moodle can access files contained in the folder. You can upload files to the folder, for example via FTP, and the new versions of the files will be used in all the courses and TaskChains that link to those files. This saves you having to update each TaskChain that uses the file.
When you create a TaskChain, you can just link to ONE of the task files (e.g. the first Hot Potatoes file). Be sure to check the "Create an alias/shorcut to this file" when you choose the file in the file-picker. Also, you should leave "Files to be added" set to "Detect automatically" on the TaskChain page. When you click the "Save ..." button, TaskChain will follow the link and try to detect ALL the other task files (e.g. Hot Potatoes files) in the repository folder that contains the task file that you linked to. Any task files that it finds will be added as a task in the TaskChain activity. Furthermore, if any of the tasks needs secondary files (e.g. images and audio files) these will also be detected on-demand automatically and a link will be created from the TaskChain activity to the secondary file in the repository. By "on-demand", I mean that the secondary files will not be linked to initiailly, but later, when the task is viewed in a browser. At this point, the browser asks Moodle to send the secondary file (e.g. image), Moodle tells TaskChain to send the file, and when TaskChain realizes the file is not yet in Moodle, it will search the repository, find the file, add a link to it, and send it to the browser. Phew! That all happens behind the scenes, with no effort required on your part.
In other words, you don't need to create all the links yourself. You just need to tell TaskChain where the first task file is and it will go and get all the other task and secondary files. As long as you plan out which files go in which folder, you leave the rest of the linking to TaskChain.
A repository can also be somewhere else completely on the internet. For example you can use your GDrive (GoodleDocs), or your DropBox as a repository. However, I have only tested TaskChain thoroughly with "File system", "Private files" and "Legacy Course files" repositories, so for other types of repository I cannot vouch for how quickly the new versions of the files are retrieved by Moodle and become available to the TaskChain activities.
all the best