Safari trouble login and bookmarks, question placing .apps in diff. folders

Hi, I am having a little bit of trouble with safari I need some help.

I downloaded opera to try out a different web browser... all was well.. Then I tried going back to safari, safari was still and still is my default browers. Anyway, I tried loging into myspace.com, to be exact, and it just sent me to the login page again. I tried login on opera, it worked.

I went to a friends mac and tried login on safari, it worked there. Yet on my mac it still does not work.

So, I deleted my cache, and reset safari, tried again still did not work. Maybe I should restart my computer?

I can get in on opera but that does not make sense.

Also, I noticed my bookmarks are missing, maybe this is after the cache thing. I don't know I am kind of new to macs. But, I did notice that the bookmarks that I had, including the pre-installed mac ones are listed under Safari bookmarks, in opera.app. Is Opera taking over my safari?

Also, this is kind of different. But I have quite a bit of apps on my computer, and I decided to list them into different files under applications. for example opera and safari are under application/internet apps... Could this affect performace, and does everything HAVE TO BE under plain applications, I would not think so, I mean some big programs automatically make a file.

Anyway, help with safari would be awesome! Anyway to reload it or something

Thanks!