Your English is quite good.
Your end goal is one that many have and is not easy to achieve. For every Facebook, Yelp, or Reddit there have been dozens of others who tried and never achieved the same kind of success for one reason or another. The thing about making websites with the goal of generating revenue is there are too many variables beyond your control. Whether or not people will like it is one thing (that is one thing you have the most control over). Search engine traffic is another thing. Whether or not people are going to share your site with their friends by clicking a Facebook like button is another. And whether or not any of your traffic translates into revenue is another thing.
You can launch a new website today, put 2 or 3 hours a week into publishing new content, put Google Adsense on it and at the end of one year make less than $10 in revenue. I had that happen. Making money was not the goal of starting the site. It was a personal interest site and some people really liked it. Sometimes I would look at the referring URLs and see people discussing my content, and sometimes outright copying entire posts (which bothered me). I would get some Facebook visitors, too. But the click-through rate was very low and the pay on clicks was sometimes as low as $0.04.
At the end of October, Yahoo/Bing killed the traffic on the site I put the most effort into. It was launched I believe in early 2006 and for all those years Yahoo sent consistent traffic to it. Google ranked it #1 for 2 weeks in early 2008 (when there was no advertising no it and no revenue) then in a matter of hours it went from #1 to sub-600 and to this day that site gets anywhere from 1 to 4 visitors per day from Google (it was getting 200 - 300 from Yahoo/Bing before they killed the traffic). The revenue from that site was $220 in October 2013. For November it was $0.
If you are in between jobs, your best option is to focus your time and effort on finding more consistent work and make websites with the goal of generating revenue as a sideline or after work hobby. Making websites requires a huge upfront investment of time with no guarantee of any payoff. Would you spend 100 hours working on something knowing you would only make $10 from it?
I think I have new and innovative ideas, too. Then I do some research and find my idea has already been done many times over.
Re-using 30% of your code is pretty good if you ask me. Investing the time to make your code re-usable is worthwhile. I have one set of database and other functionality that I use across 3 sites.
I visit the webmaster boards and I see people asking questions all the time about using a CMS in ways for which it was never intended to be used (especially Wordpress). There are plugins available? Do they do exactly what you want? Maybe, but probably not. Is the plugin author going to keep the plugin updated? Will updates come quickly after new versions of the CMS are released? Will the plugin author abandon the project leaving users who rely on it with nothing, as happens a lot? Then what about security risks? Using an open source CMS or plugin, everyone has access to the code and if a vulnerability is found, it spreads like wildfire. (I have been hacked because I failed to check for updates to open source CMSes like SMF, Joomla, and I think I got hacked through a Wordpress because I forgot to check for updates for a few days.) Then you have to consider the issue of resource usage. Some open source CMSes are big and bloated meaning that cheap shared hosting is not going to be suitable for you once you start getting traffic. Even a few thousand visitors per day will cause your host to tell you to upgrade to a VPS.
Then you have to learn the CMS. Not just how to use it to publish content, but the back-end programming of how to make it do what you want, something that may not be easy to accomplish. That alone can take 40, 80, or maybe even 100 or more hours. And when it changes, you have to learn more.
Using a CMS is like being placed inside of a box. Sometimes that box is just what you need. Other times it isn't, and you are going to have to hammer that box into the shape you need it to be. That can be a lot of work. To this day I cannot understand the benefits of using a framework and inextricably tying your code to another code base.
Determine your requirements, all the functionality you need, consider security concerns, and so forth. Then see if you can find a CMS that does the majority of what you need by default. If you can find a CMS that does 80% of what you need, then maybe you are better off going with it. The benefit of writing your own code is that you can get exactly what you want, provided you have the skill.
For blogging or basic sites, I go with Wordpress. For everything else, I will write my own code.