I hear you, my system is even slower than yours and it's getting frustrating.
Even with 2GB of RAM (I have 512MB

), running Iceweasel is a pain on those heavier desktops (such is KDE). Note that 2GB is considered very low on a desktop PC. Try installing noscript and flashblock add-ons, it should help you immensely. Java and Flash are two the most demanding requirements of normal web-browsing.
Also, disable those quirky extensions and effects on KDE, you will notice insane boost in performance. Really, your specs are enough to enjoy just about any GNU/Linux distro.
I have a suggestion. I've seen many of your posts where you were searching for absolute best desktop look, and all of them were inspired by Windows. Why don't you just install Windows 10 and be done with searching for 5-7 years? The OS looks great, you will feel at home. I heard that it's less demanding on specs than Windows 8, more like older Windows 7. I've seen it run well on laptops weaker than yours.