I will speak volumes for a Macbook Air - it's actually pretty good and satisfies everything you need above.
Good thing about Apple is that their warranty program is really good (even with or without Apple Care). My iPod Nano screwed up the other day, so I went into the Apple Store. They couldn't turn it on themselves and I was given a new one on the spot - no questions asked. Heck, they didn't even need a receipt; they just looked up the serial number lol and I saw the same thing being done with a lady having problems with her Macbook Air.
Also, the Air is really light, good as battery life, decent processor (although I would have gotten the Pro if I didn't have iMac at home) and I am currently overseas (30 +degrees every day) and it doesn't heat up. I have to say I was skeptical with the Apple OS before I got my iMac last year - but it turns out, it's actually amazing and pretty easy to get used to. The Mac is basically like an iPad - it doesn't freeze often at all. Problem is that some programs (only very few actually) don't cater for Mac. Fair point about not having the CD slot as well though - but most program installers (such as printers) for Macs don't need the disc unlike for windows, you download a separate installer. But yeah I guess you might struggle with playing DVDs and CDs without paying for an external slot?
But yeah, if $1,100 is a bit of a stretch, I would give Lenovo laptops a go - they are the equivalence of a good Windows laptop.