Yes, that's the disadvantage to a retina Macbook Pro. If you think of it like an iPad or an iPhone where you can't upgrade as well it makes more sense. You gain the slim size and nice screen.
I see a couple 15" retinas that went for about $1450 on eBay, so that might just be my target price. I just wonder if 8gb will be enough for the next 4-5 years.
That will scale terribly. Every lookup will require loading the entire file into memory in order to search it. Once the file gets too large PHP will fail to load it resulting in memory errors. Your method is guaranteed to fail in the long run.
Sounds great! Your projects are fairly common solutions, so you'll have to do something special to make them stand out. I strongly recommend using a CSS library like Bootstrap or Foundation. Also, what JavaScript library do you plan to use?
Even a single space before or after the word false will cause this problem. Make sure you don't have any other scripts throwing something into the header.
You'll have to style the more button yourself. There is some example code above to help you style it. It should not show the word false. Is there any whitespace or any other characters that might be interfering?