A good way to import tweets, blogpost, flickr photos, slideshare, I'm building a "social corner" on my website and I need to import quite a lot.  

I've got these accounts: 


Twitter
2 blog
Slideshare
Flickr
YouTube channel


I'm using the feeds-module at this moment, but for some reason, it got overwritten. 

I tried with the Media module, but I got an error every time I tried to activate the modues, so that's not an option either.

There is a pretty good module for catching and showing tweets, but there seems none like it for YouTube posts, Slideshare, Blogs, Flickr,...

What is, in your opinion, the best way to import this kind of social media every 30 minutes or so. Because I can't think of any anymore.
You're on the right track, but it sounds like your site may have some "too many modules" issues.  If you're having modules randomly overwritten or enabling is throwing errors, it is usually time to clean up the site.  If you can, start with a brand new site and only enable the modules you absolutely need.  Keep things as basic as possible.  If you want to try out other modules do it on a separate "sandbox" site that is just for testing.

There isn't going to be a single-solution for all social media.  However some places to get started:


Feeds module - for anything using RSS (YouTube does, so does SlideShare, Twitter kinda does, etc)
Specific modules could be used too like Twitter Pull and the Media module as you mentioned.