Woocommerce/Storefront issues!

Hi,
I posted this in the general section of the forum too!

I’m about to punch my PC and throw it out the window. I’m technologically inclined, I setup our entire business network of about 8 workstations and 1 main server yet I can’t seem to have wordpress and the rest of the do it yourself website features to work. This might be a long read but we are desperate now. I’ve been troubleshooting for a over a week…

3 weeks ago I started setting up our ecommerce using wordpress and woocommerce with the storefront theme… pretty basic and it does say that woocommerce and storefront are meant to be together… ok well the first couple of days I was able to add some products, pictures, color theme changes, pricing, shipping, taxes, the whole thing. I was close to finishing the majority of the site before purchasing the SSL, security, premium themes, etc. so we can go live…
I finished inserting the products a couple of days later and when I returned to the dashboard 2 days after that I get that internal server error page… I read a lot on these forums, update plugins, disable plugins, roll back scripts… it worked, the issue was Jetpack… same thing happens that same day without modifying anything major (all plugins off except woocommerce and W3 cache), just language change from English (US) to English (CA) and internal server error showed up again uninvited. From that point I wasted 2 days trying to get it back and couldn’t so I had no choice to uninstall the entire website to restart from scratch like a fresh install of Microsoft Windows. From this point on I have had all sorts of problems like if I activate storefront and woocommerce internal server error comes back, but by deleting one or the other my dashboard would come back. Tried all sorts of solutions, disabling plugins, reinstalling wordpress, activating one plugin before the other… Jetpack instantly crashes the dashboard after a fresh install when activated, after activating and deactivating woocommerce and storefront an unimaginable amount of times it suddenly starting working again… hold on… but now I can’t customise the theme, internal server error when I try to access it in the dashboard. There are some other bugs since the this began. With my expertise, the best I can describe this system (wordpress,woocommerce,storefront,etc.) is that it now feels like an Alpha build of a program, it feels unstable, fragile, anything I try to change odds are I’ll get internal server error. What makes me really angry is that it still has problems straight from a fresh install.
So basically since the 2nd main crash and full delete of files on server… I just can’t make the basic work, and I’m talking about 2 or 3 plugins at a time that’s it.
The last change I did was changing the English (US) to English (CA) again and can’t access the dashboard to change it back!

I hope someone can give me some good advice, I would much appreciate it because otherwise we won’t be able to work using wordpress and we’ll have to spend way too much on website designers meaning we won’t have an ecommerce. I’m sure I forgot some information but I hope this is enough to get things moving forward.

Extra info;
Host is Netfirms.ca
Website is http://www.TLMmachinerie.com/estore (not live).
Can’t find any error logs with FTP or Netfirms’ file manager.
Wordpress 4.2.1 initially and now 4.2.2
PHP script 5.3 (the highest available from Netfirms.ca)
I’m the one considered for the company to be the administrator and I tried contacting myself infinity amount of times and well…

Thank you!