How to configure the addon (#2)
First part available here.
Gate creation
Creating a gate is quite simple. Left click with the toolgun where you want to create one (I think you understand now!), it will open the admin menu. Select the group in the group list and the gate button will turn green. Click on it, this will appear:

The gate configuration is quite simple, as always.
You can set if the gate can be broken. If you let this unchecked, the next check will not appear. Breaking a gate could be useful: a gate has a certain amount of health you initially configured in the configuration file (all gates have the same health). A gate loses his health when vehicles drive and hurt them, depending of their speed. If you set the gate health to 200 and a vehicle caught the gate closed at 50MPH, the gate will lose 50 of health. When the gate no more has health, the gate is broken and everybody can cross it:

The gate became in its initial state after a certain amount of seconds you set in the configuration file.
The second value, Renforced Poles is a value only here to act as a lure: yeah, you tried to break a gate but due to the renforced poles you'll not be able to reach, what a pity!
Renforced Poles are invincible, and disappear when the gate retrieves its initial state.

Ok, your gate has been created. Let's say it was the gate to enter in a parking. You configured the gate and now you will need to add a machine!
Machine creation
A machine is useful for toll and parkings. There are two machines, with their own models but they work the same way and have the same features (they open the same frame basically). Let's say we want to create a Machine Enter:

There are two features: if the machine can be broken and if the machine can be hacked. These features aren't the same and if the machines allow it, it will add more realism with the criminals who will try to break your systems. If you need more explanation of what is a hacking and a cracking, please come back at the description product page on the Features tab.
When you saved it, the machine is created. A machine gate enter is here to retrieve a "virtual" ticket while a machine gate exit is here to give your ticket, calculate the price you have to pay and then give it. If you correctly understand what I mean, on a parking system you will need to place both. However, on a toll system you will only need a "Machine Gate Exit" because you just have to pay something. Create your machines and manage them how you want!

Entity edit (to-know)
You can edit as gate entities as you want by pressing left click on an entity you have created. If you press a left click on a machine gate you created, the machine gate edit frame will directly appear (you will not need to search it in the admin frame) but you also are able to change the parameters by selecting the group, the gate and the machine enter you want (if you want to change a machine enter). When you changed the pos of an entity, you must press a click on it using the toolgun and press the "EDIT" button.
Keep in mind something: everytime you save or you edit something, a cleanup of the gate entities is needed. If you forgot to press the "EDIT" button everytime you change the pos of an entity, when you will do a cleanup or when you'll save/edit something all the entities will return at their initial pos because they don't know their poses have changed since you forgot to erase the data.
Things you should know:
- For ecological reasons
(not because i'm lazy), pictures have been taken from the gmodstore script medias, that's why we are in front of edit cases and pictures are the same. - You can change everything in-game, but changing something will delete all the entities (base_gate, machine_gate enter and exit, billboard_gate) and recreate them immediatly so it can (not sure) break some things in the script if people are currently using a machine or are under a gate opened (oops the physic).
- I discourage you to change huge parameters in a group with its gates and its machines. Huge parameters mean you should not create a parking and transform it into a toll because billboard and machine enter will be broken and can cause issues. The better option is to create another group and delete this one. Take your time, when the entities will be placed everything will be good.
End of the configuration
Your configuration is done. Now you are free to use the script. Let me know if everything goes wrong!