the problem with the edits, is that if you want to use them, you can't use the originals... Your edits would be better if you could choose...
But, frankly, I think you should look at some of the rtp water tiles with the bricks or whatnot, you can still see the rest of the detail, but it is darker with white highlights scattered about to indicate that it is filled with water.
And the curtains? Well, it just doesn't look right, mostly because of the crossbar being so solid... It needs to be the same colors as the window, with no outline (VX rtp has no outlines, only shadows)
And, frankly, the fireplace fires aren't necessary because you can put an animated fire event there, which would look nicer than a static image of fire.
You have the right idea, you just need to make them seem more like the RTP (and yes, this can be done on the programs you listed... I mean, I do all my spriting in paint.exe)