Searching for a resolve

Hello guys,
I am working at a blog, using wordpress v3.0, https://www.concurspedia.com and i`ve meet some problems so far.

Problem 1:
Is there any possibility to retouch a blog and be decent view in different rezolutions? I made my blog using a 1900×1200 rez, and on lower monitors its doesnt see so nice.

Problem 2:
When i navigate on forum, “Concursuri” button -> than press on categories, after i wasnna use the navigation ( menu ) again it gives me an error. “sorry no pages found”.

Problem 3:
I wanna get some help also to resize the images from the posts. It uses the “Featured image” function of posts. https://www.concurspedia.com/category/bani/
I am trying to resize the images to a lower rez, like a banner, maybe a 600×150 rez.

Cheers,
And if needed you can contact me at [email protected]

Ty.