There are limitations to the browser which the web site has to deal with or lose the Smart TV market. Here's more about these limitations -> http://forums.cnet.com/7723-13973_102-571556/wh-samsung-smart-tv-web-browser-closed-uneexpectedly/?messageId=5354305&tag=rb_content;forums06#message5354305
I think you are asking for a Windows PC web experience. Sadly, as you discovered, that's not possible.
As to the YouTube app, I found that Google writes that so any bug or limitation there is by Google and not the TV maker.
I have a 55D8000 model and when I use the browser and go to youtube and play any videos the sound wont work. When I try other sites like dailymotion everything plays fine and I can hear sound. Whats the problem with youtube. Also whats wrong with the youtube app on the smart tv hub, any and most videos I want to play seem to be blocked or missing, yet my other LG tv which has a similar app has all the videos and nothing is blocked. I would understand if there were videos that were blocked for my region but the fact that the LG can play them from a similar app on the same Internet connection (IP geo loaction) means that the app is just stupid. Please could someone hep me with these issues as I want to be able to enjoy my TV with sound and music and watch youtube. (when I mean blocked I dont mean by parental controls I mean via blocked region videos)