Newbie to HDTV and Blu-ray - few questions.

[ulceration]

Ok a few questions. First is that I have a PS3 and a Toshiba 42RV530U LCD 1080p tv. When I set the TV to "Native" mode I get a green line at the right side of my tv, but when I see it back to "Natural" it goes away. Im wondering what this is, or if its a glitch in my TV.

Secondly, when I see within 6 or 7 feet of the TV i can sort of see blotches or blurriness when Im watching movies or playing PS3 games. If i see back 10 feet or so it looks good. I remember reading that LCD's have a "screen door effect is you sit up close" so maybe this is what theyre talking about? I dont know. I just remember I watched a scene where that was a cloud of smoke and it looked very distorted and blotchy up close. One note i should mention is that I bought a relatively generic brand HDMI cable on ebay for 12 dollars. I read that HDMI cables are HDMI cables being digital and its not like some audio cables that are analog where there is even such a thing as "better quality" cables. I first watched this same movie at my brother in laws and he has a Panasonic LCD 37" and its only 720p that he got a year ago or so and with the same PS3 and hdmi cable it looked great and i didnt notice any of this stuff up close like I am now.

Thirdly, I bought this TV for 1200 bucks and i can return it any time for 3 years because i got the circuit city advantage plan. I hear Plasma's are the best for gaming and sports but i was also trying to save a lil on my wallet. Are plasma's really THAT much better picture? Because i want to be satisfied with my purchase for years to come. Honestly so far id rate this set up a 6.75 or 7 on a scale of 10, which i think is sad because it's blu-ray high definition. Any advice or feedback is appreciated.