The whole point about this is that if you are disappointed with the machine on day one you are unlikely to change your mind. The speck on the screen is likely to be a faulty pixel. You can often resolve this by massaging the spot with a moist cotton bud, but in view of the other problem(s) it's probably not worth trying.
Laptop fans can sometimes be a little noisy, and of course they are very necessary, but if noise is a problem you should do something about it.
It seems to me that the decision almost makes itself - return the machine and exchange it for a different model. As you say, you could upgrade the RAM if you bought the Phillips, and if it's of any help I've never once used the DVD RW on my laptop.