Background process limit - Does it save data? [Stock only]

First of all, I apologize if this is in the wrong section. I was playing around with my Sony, and while attempting to figure out reverse tethering, I found the developer options which were previously hidden. I scrolled all the way down and found the option to limit background processes, and set it to no background processes. TO KEEP IT SHORT: Will setting it to no background processes save me on my monthly data plan by preventing apps from using data in the background?

LONG VERSION (for those who want to read details of why I need to know):

I've been having some issues with apps using data in the background and spending my monthly data without me knowing it. The biggest culprit there was Google Play, though there were others that were using quite a bit as well, which I now have all disabled and have been sideloading any apps I'm interested in (the issue with this would be any pro apps, but my plan was to email the developer of said app to request a way to purchase the apk through paypal, but that's another topic)

Now, whenever I look up this issue of data-hungry apps, it always comes back around to restrict background data, a setting that is not on my stock Sony Xperia Z1s, unless it is supremely hidden. One said option is to turn off all background data. Another option is to manual restrict background data for specific apps. Again, my phone has none of these options available, and I've simply gotten frustrated after reading online for many hours about this and viewing multiple seemingly simple screenshots, thinking I have finally found the solution, only to discover that my phone does NOT have the options they show on their device. No option when I go to settings/data usage/(any app) and scroll down, where it is on other devices. No restriction option when I go into settings/applications/(any app).

On Google Play, I had auto-update and notifications always off. In settings/data usage, I always have auto-sync data unchecked. I should note that my phone is not on any carrier, I'm using an AT&T Unite Go hotspot for all my texting/calling/data needs. So in settings/data usage, I selected Mobile Hotspots, and set my hotspot as such, since it states "Apps can be restricted from using these networks when in the background. Apps may also warn before using these networks for large downloads."

I've also turned to using a firewall. I have tried both NoRoot Firewall, and Mobiwol (since I am not rooted). Both experienced the same bug: the firewall itself using quite a lot of data. A lot. In fact, I ran a little test where I left wifi on, but disabled all wifi usage (foreground and back) for all apps via the firewall settings. I tested this by attempting to access my browser, and it could not load. I also kept a keen eye on the stock android data counter, to watch to see if any apps were continuing to use more data. Only Mobiwol (and previously, NoRoot Firewall), kept chowing away, and when I calculated, it had used 56kbs in a half hour, thus would be over 70mbs a month. This may not sound like a lot to you, but considering my limited data and the point that the Mobiwol devs emailed me that it should only be using mere kilobytes a month, 70mbs is a bit to swallow. Is 70mbs less than how much the hungry apps were using? Yes. But I can save even more data by not bothering with the firewall and simply disabling practically everything Google on my phone, which can be a pain in itself. But I digress...

Now that I've gone through it all, I want to know how limiting background process to none will help aid me in this issue, and if there are side-effects to doing this (such as battery life, as I'm hearing)?

If it helps, i'm running 4.4.4. KitKat. I know this is pretty long, and it wasn't exactly fun for me to type it all out either, but I hope I've given enough details for someone to help.

EDIT: I understand that apps are using more battery because since there is no background processes allowed, they aren't storing cache, and also don't launch as quick, correct? So, when it comes to background DATA, is it data in the sense of stored data not being allowed (explaining the cache not being stored), or is it talking of apps not being able to use background mobile data? Or both?